Lesson Area of Trapezoids

Transcription

1 Lesson: Supplement Area of Trapezoids Lesson Area of Trapezoids Teacher Lesson Plan CC Standards 6.G.1 Find the area of right triangles, special quadrilaterals, and polygons by composing into rectangles or decomposing into triangles and other shapes; apply these techniques in the context of solving real-world and mathematical problems. 6.G.3 Draw polygons in the coordinate plane given coordinates for the vertices; use coordinates to find the length of a side joining points with the same first coordinate or the same second coordinate. Apply these techniques in the context of solving real-world and mathematical problems. Objective The students will learn to find the area of trapezoids using a formula. Then they will get repetitive practice on finding the area of all the shapes we ve studied so far. Mathematical Practices #1 Make sense of problems and persevere in solving them #7 Look for and make sense of structure Teacher Input Bellwork: Homework: Introduction: Lesson: Review bellwork. Review previous night s homework. You may do the explore activity from the CPM textbook, lesson Whether or not you choose to do the activity may depend upon the level of your particular class. Teach according to the student notes. Extra Practice Classwork Page 3 Homework Page 5 Extra Practice Page 4 Closure Teacher selected 1 P a g e

2 Student Notes SETION 1: Defining a Trapezoid A trapezoid is a quadrilateral with one pair of parallel sides. Notice in the figure on the right that a trapezoid has two bases which are different lengths. The two bases are parallel to each other. The height of the trapezoid must be perpendicular from the top of one base to the bottom of the other. Looking at the trapezoid below, the height is a side of the trapezoid since it is perpendicular to the base. SETION 2: FINDING THE AREA OF TRAPEZOIDS USING A FORMULA Formula: Step 1: Write down your formula. Step 2: Substitute the information from the trapezoid into the formula. Step 3: Perform the operations and write you re answer in square units. Let s try these together. You Try Independent Practice 2 P a g e

3 Name Date Period: Classwork Find the area of each trapezoid below. Be sure to show where you write your formula down for each problem, plug in the number, and write your answer in square units. 3 P a g e

4 Name Date Period: Extra Practice Area Mixed Review Solve each problem below. Be sure to show where you write your formula down for each problem, plug in the number, and write your answer in square units. Which equation correctly shows how to calculate the distance between point d and point c on the coordinate plane above? A C B D P a g e

5 Name Date Period: Homework Find the area of each shape. Solve problems 5 and 6 as directed. What is the area of the parallelogram above? Which equation correctly shows how to calculate the distance between point x and point y on the coordinate plane above? A C B D P a g e

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7 SETION 1: Defining a Trapezoid Lesson Area of Trapezoids Student Notes Answer Key A trapezoid is a quadrilateral with one pair of parallel sides. Notice in the figure on the right that a trapezoid has two bases which are different lengths. The two bases are parallel to each other. The height of the trapezoid must be perpendicular from the top of one base to the bottom of the other. Looking at the trapezoid below, the height is a side of the trapezoid since it is perpendicular to the base. SETION 2: FINDING THE AREA OF TRAPEZOIDS USING A FORMULA Formula: Step 1: Write down your formula. Step 2: Substitute the information from the trapezoid into the formula. Step 3: Perform the operations and write you re answer in square units. Let s try these together. 2) 2) A = ½ (8 + 11) 6 A = 57 in² A = ½ (6 + 20) 10 A = 130 cm² You Try Independent Practice 2) 2) A = ½ (4 + 10) 5 A = 35 cm² A = ½ ( ) 12 A = 204 cm² 7 P a g e

8 Classwork Name Date Period: Answer Key Find the area of each trapezoid below. Be sure to show where you write your formula down for each problem, plug in the number, and write your answer in square units. A = ½ ( ) 13 A = ½ (3 + 7) 8 A = km² A = 40 m² A = ½ ( ) 254 A = 57,023 mi² A = ½ (15 + 8) 15 A = ft² A = ½ (7 + 9) 4 A = ½ (5 + 12) 5 A = 32 cm² A = 42.5 cm² 8 P a g e

9 Extra Practice Name Date Period: Answer Key Area Mixed Review Solve each problem below. Be sure to show where you write your formula down for each problem, plug in the number, and write your answer in square units. A = b h A = A = km² A = b h A = 6¼ 3½ A = ft² A = ½ b h A = ½ 25½ 15 A = ft² A = ½ b h A = ½ 9 18 A = 81 ft² Which equation correctly shows how to calculate the distance between point d and point c on the A = ½ (30 + 5) 100 coordinate plane above? A = 1,750 in² A C B D P a g e

10 Homework Name Date Period: Answer Key Find the area of each shape. A = ½ ( ) 3 A = ½ ( ) 11 A = in² A = 165 mm² A = ½ b h A = ½ (8 + 12) 9 A = ½ A = 90 cm² A = 50 units squared Solve problems 5 and 6 as directed. What is the area of the parallelogram above? Which equation correctly shows how to calculate A = b h the distance between point x and point y on the A = 3 2 coordinate plane above? A = 6 units squared A C B D P a g e