# Grade 7 & 8 Math Circles Circles, Circles, Circles March 19/20, 2013

Save this PDF as:

Size: px
Start display at page:

## Transcription

1 Faculty of Mathematics Waterloo, Ontario N2L 3G Introduction Grade 7 & 8 Math Circles Circles, Circles, Circles March 9/20, 203 The circle is a very important shape. In fact of all shapes, the circle is one of the two most useful shapes that exist (the other being the triangle)! But why is this? Well, circles have so many unique properties which can be used to solve many problems. Today we will focus on some of these properties and some of the applications. Review You have all worked with circles before. Let s review some properties of circles that you should already know. The circumference is the closed curved line which defines the boundary of the circle. It s similar to the perimeter of other polygons. We can use the letter C in equations. The centre of a circle is the point which is equidistant (meaning equally as far) from all points on the circumference. When drawing a circle with a compass, one leg will rest on the centre of the circle, while the the other (usually with a pencil tip) will draw the circumference. The radius of a circle is the straight line distance from the centre to any point on the circumference. Remember, since the centre is equidistant from all points on the circumference, the radius will be the same no matter which point you choose on the circumference.

2 In equations, we denote radius with r. The diameter of a circle is the length of a straight line which passes through the centre and has endpoints on the circumference. The diameter is also twice the length of the radius. Diameter is shown by d. The diagram below summarizes all this information. Circumference Radius Diameter Centre There are also a few equations which relate to properties of a circle. The length of the circumference is related to the radius. C = 2πr. Remember that the diameter is also twice the value of the radius. So we also have the equation C = πd. The equation for the area of a circle is A = πr 2 Recall that π = but we can use or even 3.4 to get a close enough estimate. Now that we ve reviewed some basic information, let s use these ideas to learn more about circles. Tangent Line Let s look at some other polygons for a while. Each polygon is regular meaning all the angles and side lengths are equal. 2

3 4 Sides 5 Sides 6 Sides 8 Sides 2 Sides 20 Sides Notice how the more sides a regular polygon has, the more it looks like a circle. In fact, the more sides there are the closer the area comes the that of a circle. If we draw a circle around each polygon with the vertices on the circumference, this fact also becomes obvious. When we do this we say that the polygons are inscribed in a circle. Here are three polygons inscribed in circle. 4 Sides 6 Sides 20 Sides So we can think of a circle as a polygon with infinitely many short sides! Now let s return to our polygons; specifically an octagon and an icosagon. Take one side of each figure and extend it on both ends like so: Since we can think of a circle as having infinitely many short sides, we can also extend one side: Notice how on the polygons, the line only touches the one side and two vertices; it never intersects with any other side. The same thing happens with a circle. However since the side length is so small, we say this line only touches one point on the circle. A long line which intersects the circumference exactly once is called a tangent line. 3

4 Here s a real world example of tangents: Take any cylindrical object, paper towel roll, a pencil or a coin, and set it on it s side on a desk. Position your head so that you re looking directly across the table. You should see the desk creates a tangent line to the circular part of the cylinder. Now for an important theorem involving tangent lines: The line drawn perpendicular to any radius line at the endpoint of the radius is the tangent line at that point on the circumference. Here s an example: More Terminology Choose any two points on the circumference of a circle and join them with a line. This line is called a chord. We ve already worked with one specific chord; the diameter. So we can define the diameter more precisely as a chord which passes though the centre of the circle. The longest chord in every circle is the diameter. Similarly, if we take any two points on a circle but this time connect them by using a section of the circumference as opposed to a straight line, we get an arc. Note there are actually two arcs between any two points; one goes clockwise and the other counter-clockwise from one point until it reaches the second point. In general, if referring to an arc between two points, the shorter arc is usually implied. One arc you ve used is the circumference. It begins and ends at the same point, so this is a special case! Now if we take the arc and the chord between two points we get an enclosed region. This region is called a segment. Since there are two possible arcs between any pair of points, there are also two segments of any points. Again, we usually assume to use the smaller arc. 4

5 Q Q Q Q P P P P Points P & Q Chord PQ Arc PQ Segment PQ Finally, the area enclosed by 2 radii (plural of radius) and an arc between the radii is called a sector. This resembles a piece of pizza or a slice of pie! Who knew math could be so tasty? The length of an arc or the area of a segment can sometimes be calculated by using fractions of a circle. Let s take and example: Circle, C, has a radius of 0cm. 5 radii are drawn around the circle, with angles equal between adjacent radii. What is the length of the arc and area of the sector between any two adjacent radii? Be sure to include a diagram in your solution. 5

6 Angles Though using fractions can be nice when calculating arc length or area of a sector, most times there won t be a nice fraction. Instead we can use the angle separating two radii which work out nicely with more numbers. However, even when we use degrees many numbers won t work out nicely. This is why mathematicians don t like to use degrees but a more convenient units called radians. But what is a radian? Let s begin by drawing an equilateral triangle with side lengths of unit. Now take the one edge and pull it so the line is curved but still has a length of unit. You ll get something like this: What part of a circle is this? z With similar triangles, all angles will be the same and the proportions of the side lengths will remain the same though the actual lengths may differ. The same can be said for similar sectors. So if we take the above sector, a similar sector will also have the same proportions between side lengths, though the lengths themselves may differ, and the same angle z. We define radian or rad to be the size of angle z. Now let s extend this concept. How many radians are in a circle? First notice that the length of the arc is unit, as is the radius of the circle which this sector was taken from. If we calculate the circumference using C = 2πr, we get C = 2π. In this specific circle, there is a direct correlation between arc length and angle (in radians). So in a circle there are 360 or 2π radians. The following diagrams should help explain further. 6

8 Circles & Triangles Recall that the two most important shapes that exist are the circle and the triangle. Both are actually very closely related. When we were investigating the number of sides or edges a circle has, remember that we only looked at regular polygons. When we inscribed each polygon in a circle, all the corners or vertices were on the circumference of the circle. Some irregular polygons can be inscribed so that this property (of vertices intersecting the circumference) holds. Simply select a number of points on the circumference of a circle, and draw chords between all adjacent points. Draw an irregular hexagon which is inscribed in the circle below. However, there are many irregular polygons which cannot be inscribed where all vertices intersect with the circumference. The one exception is the triangle. Every triangle can be inscribed by a circle so that all three vertices intersect with the circumference. To inscribe a triangle in a circle, we will need two tools: a compass and a ruler, as well as a triangle to be inscribed. Use the following process to inscribe a triangle.. Observe the longest edge of your triangle. If two or all three edges are similar in length, simply select one. 8

9 2. Separate the legs of the compass so that the distance between the point and pencil is about 3 4 the length of the line you selected in Step. 3. Using your compass, draw 3 circles, each one centred at a vertex of the triangle. Be sure not to alter the spread of your compass! The 3 circles will cross over one another. You should have something like this: 4. Choose 2 of the circles you have drawn. The circumferences of these circles will intersect in two locations. Using a ruler, draw a line which connects both points. Ensure this line is extended past these points. 5. Repeat Step 4 with the other two combinations of circles. You should get this: 6. Each line is actually perpendicular to one of the edges of the triangle. As well, it divides that same edge into 2 equal halves. This is why these lines are called perpendicular bisectors. 7. Notice that the 3 perpendicular bisectors intersect at one point. This will always happen if you draw your lines correctly! This intersection point is called the circumcentre. It becomes the centre of the circle which inscribes the triangle. 8. Place the point of your compass on the circumcentre. Extend the other leg to any of the vertices of the triangle. Now draw the circle around the circumcentre, and it will inscribe the triangle. 9

10 We have dealt with many theoretical applications of circles. There are SO MANY MORE that we simply don t have time to cover! By completing the problem set you will see some of the applications of the theory we did cover. Problems. Given the following circle, measure the radius and chord length, then calculate the diameter, circumference, arc length, area of the whole circle, and the area of the sector. 45 o 2. Given the following radii and angle between them, calculate the arc length and sector area. (a) 3cm, 2 rad (b) 2m, 35 (c) 25cm, Circle C, with centre O, has two radii which are 5cm long. One radii ends (on the circumference) at point A and the other ends at point B (also on the circumference). If angle AOB is π rad, what is the length of chord AB? (Hint: Draw a diagram and 2 also use Pythagorean Theorem) 0

11 4. Given the following figure, what is the area of the shaded region if the diameter of the large circle is 6cm and all of the smaller circles have the same radius? What is the radius of a circle with an equivalent area? 5. CHALLENGE: What is the total area of all the darker shaded petals, if all the circles have a radius of 2cm? Note all the petals are the same size and don t overlap one another. Also the vertices of each petal intersect with three other petal vertices.

12 6. Inscribe the following triangles in a circle. (a) 2

13 (b) 3

14 7. Take the following equilateral triangle and find the circumcentre C, as normal. Draw the circle which inscribes the triangle. Also draw another circle, centred at C, which is inscribed by the triangle. You will notice that the sides of the triangle are tangent to the circle at the points where the perpendicular bisectors intersect with the triangle s sides. 4

15 8. Given the irregular octagon below, find the circumcentre using the same process as for triangles. Then inscribe this figure in a circle. 5

### Radius, diameter, circumference, π (Pi), central angles, Pythagorean relationship. about CIRCLES

Grade 9 Math Unit 8 : CIRCLE GEOMETRY NOTES 1 Chapter 8 in textbook (p. 384 420) 5/50 or 10% on 2011 CRT: 5 Multiple Choice WHAT YOU SHOULD ALREADY KNOW: Radius, diameter, circumference, π (Pi), central

### Junior Math Circles November 18, D Geometry II

1 University of Waterloo Faculty of Mathematics Junior Math Circles November 18, 009 D Geometry II Centre for Education in Mathematics and Computing Two-dimensional shapes have a perimeter and an area.

### Angles that are between parallel lines, but on opposite sides of a transversal.

GLOSSARY Appendix A Appendix A: Glossary Acute Angle An angle that measures less than 90. Acute Triangle Alternate Angles A triangle that has three acute angles. Angles that are between parallel lines,

### Set 1: Circumference, Angles, Arcs, Chords, and Inscribed Angles

Goal: To provide opportunities for students to develop concepts and skills related to circumference, arc length, central angles, chords, and inscribed angles Common Core Standards Congruence Experiment

### CSU Fresno Problem Solving Session. Geometry, 17 March 2012

CSU Fresno Problem Solving Session Problem Solving Sessions website: http://zimmer.csufresno.edu/ mnogin/mfd-prep.html Math Field Day date: Saturday, April 21, 2012 Math Field Day website: http://www.csufresno.edu/math/news

### CK-12 Geometry: Parts of Circles and Tangent Lines

CK-12 Geometry: Parts of Circles and Tangent Lines Learning Objectives Define circle, center, radius, diameter, chord, tangent, and secant of a circle. Explore the properties of tangent lines and circles.

### Area. Area Overview. Define: Area:

Define: Area: Area Overview Kite: Parallelogram: Rectangle: Rhombus: Square: Trapezoid: Postulates/Theorems: Every closed region has an area. If closed figures are congruent, then their areas are equal.

### Sec 1.1 CC Geometry - Constructions Name: 1. [COPY SEGMENT] Construct a segment with an endpoint of C and congruent to the segment AB.

Sec 1.1 CC Geometry - Constructions Name: 1. [COPY SEGMENT] Construct a segment with an endpoint of C and congruent to the segment AB. A B C **Using a ruler measure the two lengths to make sure they have

### Postulate 17 The area of a square is the square of the length of a. Postulate 18 If two figures are congruent, then they have the same.

Chapter 11: Areas of Plane Figures (page 422) 11-1: Areas of Rectangles (page 423) Rectangle Rectangular Region Area is measured in units. Postulate 17 The area of a square is the square of the length

### 2006 Geometry Form A Page 1

2006 Geometry Form Page 1 1. he hypotenuse of a right triangle is 12" long, and one of the acute angles measures 30 degrees. he length of the shorter leg must be: () 4 3 inches () 6 3 inches () 5 inches

### Circle Name: Radius: Diameter: Chord: Secant:

12.1: Tangent Lines Congruent Circles: circles that have the same radius length Diagram of Examples Center of Circle: Circle Name: Radius: Diameter: Chord: Secant: Tangent to A Circle: a line in the plane

### The measure of an arc is the measure of the central angle that intercepts it Therefore, the intercepted arc measures

8.1 Name (print first and last) Per Date: 3/24 due 3/25 8.1 Circles: Arcs and Central Angles Geometry Regents 2013-2014 Ms. Lomac SLO: I can use definitions & theorems about points, lines, and planes to

### Student Name: Teacher: Date: District: Miami-Dade County Public Schools Assessment: 9_12 Mathematics Geometry Exam 3. Form: 201

Student Name: Teacher: District: Date: Miami-Dade County Public Schools Assessment: 9_12 Mathematics Geometry Exam 3 Description: Geometry Topic 6: Circles Form: 201 1. Which method is valid for proving

### 39 Symmetry of Plane Figures

39 Symmetry of Plane Figures In this section, we are interested in the symmetric properties of plane figures. By a symmetry of a plane figure we mean a motion of the plane that moves the figure so that

### Objective: To distinguish between degree and radian measure, and to solve problems using both.

CHAPTER 3 LESSON 1 Teacher s Guide Radian Measure AW 3.2 MP 4.1 Objective: To distinguish between degree and radian measure, and to solve problems using both. Prerequisites Define the following concepts.

### Centroid: The point of intersection of the three medians of a triangle. Centroid

Vocabulary Words Acute Triangles: A triangle with all acute angles. Examples 80 50 50 Angle: A figure formed by two noncollinear rays that have a common endpoint and are not opposite rays. Angle Bisector:

### GAP CLOSING. 2D Measurement. Intermediate / Senior Student Book

GAP CLOSING 2D Measurement Intermediate / Senior Student Book 2-D Measurement Diagnostic...3 Areas of Parallelograms, Triangles, and Trapezoids...6 Areas of Composite Shapes...14 Circumferences and Areas

### Chapters 6 and 7 Notes: Circles, Locus and Concurrence

Chapters 6 and 7 Notes: Circles, Locus and Concurrence IMPORTANT TERMS AND DEFINITIONS A circle is the set of all points in a plane that are at a fixed distance from a given point known as the center of

### 16 Circles and Cylinders

16 Circles and Cylinders 16.1 Introduction to Circles In this section we consider the circle, looking at drawing circles and at the lines that split circles into different parts. A chord joins any two

### GEOMETRIC MENSURATION

GEOMETRI MENSURTION Question 1 (**) 8 cm 6 cm θ 6 cm O The figure above shows a circular sector O, subtending an angle of θ radians at its centre O. The radius of the sector is 6 cm and the length of the

### Inscribed Angle Theorem and Its Applications

: Student Outcomes Prove the inscribed angle theorem: The measure of a central angle is twice the measure of any inscribed angle that intercepts the same arc as the central angle. Recognize and use different

### Grade 7/8 Math Circles Greek Constructions - Solutions October 6/7, 2015

Faculty of Mathematics Waterloo, Ontario N2L 3G1 Centre for Education in Mathematics and Computing Grade 7/8 Math Circles Greek Constructions - Solutions October 6/7, 2015 Mathematics Without Numbers The

### Chapter 6 Notes: Circles

Chapter 6 Notes: Circles IMPORTANT TERMS AND DEFINITIONS A circle is the set of all points in a plane that are at a fixed distance from a given point known as the center of the circle. Any line segment

### PERIMETER AND AREA. In this unit, we will develop and apply the formulas for the perimeter and area of various two-dimensional figures.

PERIMETER AND AREA In this unit, we will develop and apply the formulas for the perimeter and area of various two-dimensional figures. Perimeter Perimeter The perimeter of a polygon, denoted by P, is the

### Lesson 1: Introducing Circles

IRLES N VOLUME Lesson 1: Introducing ircles ommon ore Georgia Performance Standards M9 12.G..1 M9 12.G..2 Essential Questions 1. Why are all circles similar? 2. What are the relationships among inscribed

### (a) 5 square units. (b) 12 square units. (c) 5 3 square units. 3 square units. (d) 6. (e) 16 square units

1. Find the area of parallelogram ACD shown below if the measures of segments A, C, and DE are 6 units, 2 units, and 1 unit respectively and AED is a right angle. (a) 5 square units (b) 12 square units

### Overview Mathematical Practices Congruence

Overview Mathematical Practices Congruence 1. Make sense of problems and persevere in Experiment with transformations in the plane. solving them. Understand congruence in terms of rigid motions. 2. Reason

### Perimeter and area formulas for common geometric figures:

Lesson 10.1 10.: Perimeter and Area of Common Geometric Figures Focused Learning Target: I will be able to Solve problems involving perimeter and area of common geometric figures. Compute areas of rectangles,

### Grade 7/8 Math Circles February 10/11, 2015 Pi

Faculty of Mathematics Waterloo, Ontario N2L 3G1 Centre for Education in Mathematics and Computing The Best Tasting Number Grade 7/8 Math Circles February 10/11, 2015 Pi Today, we re going to talk about

### Lesson 2: Circles, Chords, Diameters, and Their Relationships

Circles, Chords, Diameters, and Their Relationships Student Outcomes Identify the relationships between the diameters of a circle and other chords of the circle. Lesson Notes Students are asked to construct

### Activity Set 4. Trainer Guide

Geometry and Measurement of Plane Figures Activity Set 4 Trainer Guide Int_PGe_04_TG GEOMETRY AND MEASUREMENT OF PLANE FIGURES Activity Set #4 NGSSS 3.G.3.1 NGSSS 3.G.3.3 NGSSS 4.G.5.1 NGSSS 5.G.3.1 Amazing

### Applications of Trigonometry

chapter 6 Tides on a Florida beach follow a periodic pattern modeled by trigonometric functions. Applications of Trigonometry This chapter focuses on applications of the trigonometry that was introduced

### Unit 3: Circles and Volume

Unit 3: Circles and Volume This unit investigates the properties of circles and addresses finding the volume of solids. Properties of circles are used to solve problems involving arcs, angles, sectors,

### MATH STUDENT BOOK. 8th Grade Unit 6

MATH STUDENT BOOK 8th Grade Unit 6 Unit 6 Measurement Math 806 Measurement Introduction 3 1. Angle Measures and Circles 5 Classify and Measure Angles 5 Perpendicular and Parallel Lines, Part 1 12 Perpendicular

### Unit 3 Circles and Spheres

Accelerated Mathematics I Frameworks Student Edition Unit 3 Circles and Spheres 2 nd Edition March, 2011 Table of Contents INTRODUCTION:... 3 Sunrise on the First Day of a New Year Learning Task... 8 Is

### Solutions to Exercises, Section 6.1

Instructor s Solutions Manual, Section 6.1 Exercise 1 Solutions to Exercises, Section 6.1 1. Find the area of a triangle that has sides of length 3 and 4, with an angle of 37 between those sides. 3 4 sin

### Practical Geometry. Chapter Introduction

Practical Geometry Chapter 14 14.1 Introduction We see a number of shapes with which we are familiar. We also make a lot of pictures. These pictures include different shapes. We have learnt about some

### Perfume Packaging. Ch 5 1. Chapter 5: Solids and Nets. Chapter 5: Solids and Nets 279. The Charles A. Dana Center. Geometry Assessments Through

Perfume Packaging Gina would like to package her newest fragrance, Persuasive, in an eyecatching yet cost-efficient box. The Persuasive perfume bottle is in the shape of a regular hexagonal prism 10 centimeters

### Solutions to Exercises, Section 5.2

Instructor s Solutions Manual, Section 5.2 Exercise 1 Solutions to Exercises, Section 5.2 In Exercises 1 8, convert each angle to radians. 1. 15 Start with the equation Divide both sides by 360 to obtain

### Geometry Notes PERIMETER AND AREA

Perimeter and Area Page 1 of 57 PERIMETER AND AREA Objectives: After completing this section, you should be able to do the following: Calculate the area of given geometric figures. Calculate the perimeter

### Geometry Vocabulary. Created by Dani Krejci referencing:

Geometry Vocabulary Created by Dani Krejci referencing: http://mrsdell.org/geometry/vocabulary.html point An exact location in space, usually represented by a dot. A This is point A. line A straight path

### Surface Area and Volume Cylinders, Cones, and Spheres

Surface Area and Volume Cylinders, Cones, and Spheres Michael Fauteux Rosamaria Zapata CK12 Editor Say Thanks to the Authors Click http://www.ck12.org/saythanks (No sign in required) To access a customizable

### Education Resources. This section is designed to provide examples which develop routine skills necessary for completion of this section.

Education Resources Circle Higher Mathematics Supplementary Resources Section A This section is designed to provide examples which develop routine skills necessary for completion of this section. R1 I

### GAP CLOSING. 2D Measurement GAP CLOSING. Intermeditate / Senior Facilitator s Guide. 2D Measurement

GAP CLOSING 2D Measurement GAP CLOSING 2D Measurement Intermeditate / Senior Facilitator s Guide 2-D Measurement Diagnostic...4 Administer the diagnostic...4 Using diagnostic results to personalize interventions...4

### Arc Length and Areas of Sectors

Student Outcomes When students are provided with the angle measure of the arc and the length of the radius of the circle, they understand how to determine the length of an arc and the area of a sector.

### NCERT. Area of the circular path formed by two concentric circles of radii. Area of the sector of a circle of radius r with central angle θ =

AREA RELATED TO CIRCLES (A) Main Concepts and Results CHAPTER 11 Perimeters and areas of simple closed figures. Circumference and area of a circle. Area of a circular path (i.e., ring). Sector of a circle

### GEOMETRY. Constructions OBJECTIVE #: G.CO.12

GEOMETRY Constructions OBJECTIVE #: G.CO.12 OBJECTIVE Make formal geometric constructions with a variety of tools and methods (compass and straightedge, string, reflective devices, paper folding, dynamic

### Algebra Geometry Glossary. 90 angle

lgebra Geometry Glossary 1) acute angle an angle less than 90 acute angle 90 angle 2) acute triangle a triangle where all angles are less than 90 3) adjacent angles angles that share a common leg Example:

### Geometry SOL G.11 G.12 Circles Study Guide

Geometry SOL G.11 G.1 Circles Study Guide Name Date Block Circles Review and Study Guide Things to Know Use your notes, homework, checkpoint, and other materials as well as flashcards at quizlet.com (http://quizlet.com/4776937/chapter-10-circles-flashcardsflash-cards/).

### Geometry. Higher Mathematics Courses 69. Geometry

The fundamental purpose of the course is to formalize and extend students geometric experiences from the middle grades. This course includes standards from the conceptual categories of and Statistics and

### 43 Perimeter and Area

43 Perimeter and Area Perimeters of figures are encountered in real life situations. For example, one might want to know what length of fence will enclose a rectangular field. In this section we will study

### CIRCLE DEFINITIONS AND THEOREMS

DEFINITIONS Circle- The set of points in a plane equidistant from a given point(the center of the circle). Radius- A segment from the center of the circle to a point on the circle(the distance from the

### 56 questions (multiple choice, check all that apply, and fill in the blank) The exam is worth 224 points.

6.1.1 Review: Semester Review Study Sheet Geometry Core Sem 2 (S2495808) Semester Exam Preparation Look back at the unit quizzes and diagnostics. Use the unit quizzes and diagnostics to determine which

### Geometry Unit 7 (Textbook Chapter 9) Solving a right triangle: Find all missing sides and all missing angles

Geometry Unit 7 (Textbook Chapter 9) Name Objective 1: Right Triangles and Pythagorean Theorem In many geometry problems, it is necessary to find a missing side or a missing angle of a right triangle.

### SHAPE, SPACE AND MEASURES

SHAPE, SPACE AND MEASURES Pupils should be taught to: Use accurately the vocabulary, notation and labelling conventions for lines, angles and shapes; distinguish between conventions, facts, definitions

### CCGPS UNIT 3 Semester 1 ANALYTIC GEOMETRY Page 1 of 32. Circles and Volumes Name:

GPS UNIT 3 Semester 1 NLYTI GEOMETRY Page 1 of 3 ircles and Volumes Name: ate: Understand and apply theorems about circles M9-1.G..1 Prove that all circles are similar. M9-1.G.. Identify and describe relationships

### Taxicab Geometry, or When a Circle is a Square. Circle on the Road 2012, Math Festival

Taxicab Geometry, or When a Circle is a Square Circle on the Road 2012, Math Festival Olga Radko (Los Angeles Math Circle, UCLA) April 14th, 2012 Abstract The distance between two points is the length

### Trigonometric Functions and Triangles

Trigonometric Functions and Triangles Dr. Philippe B. Laval Kennesaw STate University August 27, 2010 Abstract This handout defines the trigonometric function of angles and discusses the relationship between

### Grade 7/8 Math Circles February 10/11, 2015 Pi Solutions

Faculty of Mathematics Waterloo, Ontario N2L 3G1 Centre for Education in Mathematics and Computing The Best Tasting Number Grade 7/8 Math Circles February 10/11, 2015 Pi Solutions Today, we re going to

### Name Geometry Exam Review #1: Constructions and Vocab

Name Geometry Exam Review #1: Constructions and Vocab Copy an angle: 1. Place your compass on A, make any arc. Label the intersections of the arc and the sides of the angle B and C. 2. Compass on A, make

### Geometry Enduring Understandings Students will understand 1. that all circles are similar.

High School - Circles Essential Questions: 1. Why are geometry and geometric figures relevant and important? 2. How can geometric ideas be communicated using a variety of representations? ******(i.e maps,

### 1 Solution of Homework

Math 3181 Dr. Franz Rothe February 4, 2011 Name: 1 Solution of Homework 10 Problem 1.1 (Common tangents of two circles). How many common tangents do two circles have. Informally draw all different cases,

### Topics Covered on Geometry Placement Exam

Topics Covered on Geometry Placement Exam - Use segments and congruence - Use midpoint and distance formulas - Measure and classify angles - Describe angle pair relationships - Use parallel lines and transversals

### New York State Student Learning Objective: Regents Geometry

New York State Student Learning Objective: Regents Geometry All SLOs MUST include the following basic components: Population These are the students assigned to the course section(s) in this SLO all students

### NCERT. In examples 1 and 2, write the correct answer from the given four options.

MTHEMTIS UNIT 2 GEOMETRY () Main oncepts and Results line segment corresponds to the shortest distance between two points. The line segment joining points and is denoted as or as. ray with initial point

### Conjectures for Geometry for Math 70 By I. L. Tse

Conjectures for Geometry for Math 70 By I. L. Tse Chapter Conjectures 1. Linear Pair Conjecture: If two angles form a linear pair, then the measure of the angles add up to 180. Vertical Angle Conjecture:

### Circles, Angles, & Arcs

Lesson 27 Lesson 27, page 1 of 12 Glencoe Geometry Chapter 9.1 & 9.2 Circles, Angles, & Arcs What would our world be without circles? From car tires, to CDs and DVDs, to gears, and crop circles, the circle

### G7-3 Measuring and Drawing Angles and Triangles Pages

G7-3 Measuring and Drawing Angles and Triangles Pages 102 104 Curriculum Expectations Ontario: 5m51, 5m52, 5m54, 6m48, 6m49, 7m3, 7m4, 7m46 WNCP: 6SS1, review, [T, R, V] Vocabulary angle vertex arms acute

### GEOMETRY COMMON CORE STANDARDS

1st Nine Weeks Experiment with transformations in the plane G-CO.1 Know precise definitions of angle, circle, perpendicular line, parallel line, and line segment, based on the undefined notions of point,

### Congruence. Set 5: Bisectors, Medians, and Altitudes Instruction. Student Activities Overview and Answer Key

Instruction Goal: To provide opportunities for students to develop concepts and skills related to identifying and constructing angle bisectors, perpendicular bisectors, medians, altitudes, incenters, circumcenters,

### Geometry Unit 6 Areas and Perimeters

Geometry Unit 6 Areas and Perimeters Name Lesson 8.1: Areas of Rectangle (and Square) and Parallelograms How do we measure areas? Area is measured in square units. The type of the square unit you choose

### San Jose Math Circle February 14, 2009 CIRCLES AND FUNKY AREAS - PART II. Warm-up Exercises

San Jose Math Circle February 14, 2009 CIRCLES AND FUNKY AREAS - PART II Warm-up Exercises 1. In the diagram below, ABC is equilateral with side length 6. Arcs are drawn centered at the vertices connecting

### of one triangle are congruent to the corresponding parts of the other triangle, the two triangles are congruent.

2901 Clint Moore Road #319, Boca Raton, FL 33496 Office: (561) 459-2058 Mobile: (949) 510-8153 Email: HappyFunMathTutor@gmail.com www.happyfunmathtutor.com GEOMETRY THEORUMS AND POSTULATES GEOMETRY POSTULATES:

Unit 6: POLYGONS Are these polygons? Justify your answer by explaining WHY or WHY NOT??? a) b) c) Yes or No Why/Why not? Yes or No Why/Why not? Yes or No Why/Why not? a) What is a CONCAVE polygon? Use

### INFORMATION FOR TEACHERS

INFORMATION FOR TEACHERS The math behind DragonBox Elements - explore the elements of geometry - Includes exercises and topics for discussion General information DragonBox Elements Teaches geometry through

### Geometry Vocabulary Booklet

Geometry Vocabulary Booklet Geometry Vocabulary Word Everyday Expression Example Acute An angle less than 90 degrees. Adjacent Lying next to each other. Array Numbers, letter or shapes arranged in a rectangular

### Warm Up #23: Review of Circles 1.) A central angle of a circle is an angle with its vertex at the of the circle. Example:

Geometr hapter 12 Notes - 1 - Warm Up #23: Review of ircles 1.) central angle of a circle is an angle with its verte at the of the circle. Eample: X 80 2.) n arc is a section of a circle. Eamples:, 3.)

### Chapter 5 Athens Let no one ignorant of geometry enter my door-plato s Academy

43 Chapter 5 Athens Let no one ignorant of geometry enter my door-plato s Academy It was perhaps the devastating discovery of the irrationality of the square root of that sent such quivers down the Greek

### Unit 3: Triangle Bisectors and Quadrilaterals

Unit 3: Triangle Bisectors and Quadrilaterals Unit Objectives Identify triangle bisectors Compare measurements of a triangle Utilize the triangle inequality theorem Classify Polygons Apply the properties

### 3. Lengths and areas associated with the circle including such questions as: (i) What happens to the circumference if the radius length is doubled?

1.06 Circle Connections Plan The first two pages of this document show a suggested sequence of teaching to emphasise the connections between synthetic geometry, co-ordinate geometry (which connects algebra

### Section 9-1. Basic Terms: Tangents, Arcs and Chords Homework Pages 330-331: 1-18

Chapter 9 Circles Objectives A. Recognize and apply terms relating to circles. B. Properly use and interpret the symbols for the terms and concepts in this chapter. C. Appropriately apply the postulates,

### 9 Area, Perimeter and Volume

9 Area, Perimeter and Volume 9.1 2-D Shapes The following table gives the names of some 2-D shapes. In this section we will consider the properties of some of these shapes. Rectangle All angles are right

### Draft copy. Circles, cylinders and prisms. Circles

12 Circles, cylinders and prisms You are familiar with formulae for area and volume of some plane shapes and solids. In this chapter you will build on what you learnt in Mathematics for Common Entrance

### Integrated Algebra: Geometry

Integrated Algebra: Geometry Topics of Study: o Perimeter and Circumference o Area Shaded Area Composite Area o Volume o Surface Area o Relative Error Links to Useful Websites & Videos: o Perimeter and

### 10.1: Areas of Parallelograms and Triangles

10.1: Areas of Parallelograms and Triangles Important Vocabulary: By the end of this lesson, you should be able to define these terms: Base of a Parallelogram, Altitude of a Parallelogram, Height of a

### Objectives. Cabri Jr. Tools

^Åíáîáíó=NO Objectives To learn how to construct all types of triangles using the Cabri Jr. application To reinforce the difference between a construction and a drawing Cabri Jr. Tools fåíêççìåíáçå `çåëíêìåíáåö

### Surface Area of Rectangular & Right Prisms Surface Area of Pyramids. Geometry

Surface Area of Rectangular & Right Prisms Surface Area of Pyramids Geometry Finding the surface area of a prism A prism is a rectangular solid with two congruent faces, called bases, that lie in parallel

### Geometry Chapter 10 Study Guide Name

eometry hapter 10 Study uide Name Terms and Vocabulary: ill in the blank and illustrate. 1. circle is defined as the set of all points in a plane that are equidistant from a fixed point called the center.

### ARC MEASURMENT BASED ON THE MEASURMENT OF A CENTRAL ANGLE

ARC MEASURMENT BASED ON THE MEASURMENT OF A CENTRAL ANGLE Keywords: Central angle An angle whose vertex is the center of a circle and whose sides contain the radii of the circle Arc Two points on a circle

### Conjectures. Chapter 2. Chapter 3

Conjectures Chapter 2 C-1 Linear Pair Conjecture If two angles form a linear pair, then the measures of the angles add up to 180. (Lesson 2.5) C-2 Vertical Angles Conjecture If two angles are vertical

### Geometry in a Nutshell

Geometry in a Nutshell Henry Liu, 26 November 2007 This short handout is a list of some of the very basic ideas and results in pure geometry. Draw your own diagrams with a pencil, ruler and compass where

### Geometry - Semester 2. Mrs. Day-Blattner 1/20/2016

Geometry - Semester 2 Mrs. Day-Blattner 1/20/2016 Agenda 1/20/2016 1) 20 Question Quiz - 20 minutes 2) Jan 15 homework - self-corrections 3) Spot check sheet Thales Theorem - add to your response 4) Finding

### Circumference and area of a circle

c Circumference and area of a circle 22 CHAPTER 22.1 Circumference of a circle The circumference is the special name of the perimeter of a circle, that is, the distance all around it. Measure the circumference

Chapter Additional Topics in Math In addition to the questions in Heart of Algebra, Problem Solving and Data Analysis, and Passport to Advanced Math, the SAT Math Test includes several questions that are

### Geometry Honors: Extending 2 Dimensions into 3 Dimensions. Unit Overview. Student Focus. Semester 2, Unit 5: Activity 30. Resources: Online Resources:

Geometry Honors: Extending 2 Dimensions into 3 Dimensions Semester 2, Unit 5: Activity 30 Resources: SpringBoard- Geometry Online Resources: Geometry Springboard Text Unit Overview In this unit students

### 1) Perpendicular bisector 2) Angle bisector of a line segment

1) Perpendicular bisector 2) ngle bisector of a line segment 3) line parallel to a given line through a point not on the line by copying a corresponding angle. 1 line perpendicular to a given line through

### Circle geometry theorems

Circle geometry theorems http://topdrawer.aamt.edu.au/geometric-reasoning/big-ideas/circlegeometry/angle-and-chord-properties Theorem Suggested abbreviation Diagram 1. When two circles intersect, the line

### PRACTICAL GEOMETRY SYMMETRY AND VISUALISING SOLID SHAPES NCERT

UNIT 12 PRACTICAL GEOMETRY SYMMETRY AND VISUALISING SOLID SHAPES (A) Main Concepts and Results Let a line l and a point P not lying on it be given. By using properties of a transversal and parallel lines,