Module 9: Creating Triangles from Angle Measures

Module 9

Lesson 3

I CAN create triangles with given angle measures.

Multiple Choice

Which tool is a protractor?

Make a triangle starting with an angle measure of 70°

​Use a protractor and a pencil. Fold paper in half.

Once you create your angle of 70°, draw a straight line connecting your 2 rays.

Measure the 3 inside angles of the triangle.

What do they measure up to?

​?

​?

​Name:

Date:

Period:

​Using the same paper...

Try to draw 2 triangles:

The first has the angle measurements of 30°, 70°, 110°

The second has the angle measurements of 45°, 50°, 60°

Discussion:

Were you able to make triangles?

Describe what happened.

​On the back side of your paper...

Tony and Kara are making quilts. They are cutting triangle shapes for their quilt. The triangles have angle measures of 45°, 45°, and 90°. The pattern for the triangles Kara is using is shown.

​Try to draw two 45°, 45°, 90° triangles that are 2 different sizes. One bigger or smaller than the first.

​As you can see, it is possible to make triangles of different sizes even if they have the same angle measurements.

​​Smaller Triangle

​This is called SCALING. Remember that scaling is making something bigger or smaller with the same proportions or the same shape.

Larger Triangle

Dropdown

I ​

Select answer

make a triangle with angles of 25°, 75°, and 80°.

Dropdown

I ​

Select answer

make a triangle with angles of 20°, 70°, and 110°.

Multiple Choice

Triangles have angle measures that add up to:

• 180°

• 120°

• 270°

• 90°

​In the last spot on the back of your paper...

Draw a triangle with the measures of 60°, 60°, 60°

Open Ended

What can you tell me about the triangle you drew with the angle measures of 60°, 60°, 60°?

• Mr. Wellner

" Turn in your papers "