Geometry Nomenclature: Triangles

Transcription

1 Geometry Nomenclature: Triangles Activity 1 Teach the parts of a triangle first. Students can make one out of construction paper and use the cards to label the parts. Activity 2 Teach the different types of triangles based on the number of sides that are the same. Scalene triangles have 3 sides that are all different, isosceles triangles have two sides that are the same and equilateral triangles have three equal sides. Students can use a ruler to measure. See if they can find examples in the environment. Activity 3 Teach the different types of triangles based on angles. First show how to use a measuring angle (right angle) to see if angles are the same, smaller or larger. Acute angles are smaller and obtuse angles are larger. Children enjoy using a measuring angle to find different types of these angles in the environment. Children can then identify triangles that have these angles. One example of each should be recorded on paper. Activity 4 After they have learned the terminology they can name triangles such as obtuse-angled scalene triangle. Activity 5 Play the detective game of triangles. Traditionally there are 54 triangles in three sizes and three colors. Start by writing the triangle on paper. Add a clue such as red. There are still too many choices. Add another clue such as small. The children will quickly see they need all the clues: The small red obtuse-angled scalene triangle. Once they understand the game they must find or draw the triangles described.

2 base of the triangle base of the triangle angle angle

3 vertex vertex sides of a triangle sides of a triangle

4 area of a triangle area of a triangle perimeter of a triangle perimeter of a triangle

5 right triangle right triangle obtuse triangle obtuse triangle

6 acute triangle acute triangle equilateral triangle equilateral triangle

7 scalene triangle scalene triangle isosceles triangle isosceles triangle

8 The is any side of the triangle where the triangle is resting. The base of the triangle is any side of the triangle where the triangle is resting. An is where two sides meet at a common endpoint. An angle is where two sides meet at a common endpoint.

9 The is the common endpoint of two sides. The vertex is the common endpoint of two sides. The are the line segments that form the triangle. The sides of a triangle are the line segments that form the triangle.

10 The is the plane inside the sides of the triangle. The area of a triangle is the plane inside the sides of the triangle. The is the distance around the triangle. The perimeter of a triangle is the distance around the triangle.

11 A is a triangle that has one right angle which measures 90 degrees. A right triangle is a triangle that has one right angle which measures 90 degrees. An is a triangle that has one obtuse angle which is larger than a 90 degree right angle. An obtuse triangle is a triangle that has one obtuse angle which is larger than a 90 degree right angle.

12 An is a triangle with three acute angles which are smaller than a 90 degree right angle. An acute triangle is a triangle with three acute angles which are smaller than a 90 degree right angle. An is a triangle with three equal sides and three equal angles. An equilateral triangle is a triangle with three equal sides and three equal angles.

13 A is a triangle with no equal sides. A scalene triangle is a triangle with no equal sides. An is a triangle with two sides that are equal. An isosceles triangle is a triangle with two sides that are equal.