Angles Objectives 1 Name and classify angles 2

Angles

Objectives 1) Name and classify angles. 2) Define complementary and supplementary angles. 3) Apply definitions of complementary and supplementary angles.

Possible Names for this angle: 1 R SRT TRS

We do: Example 1 B How many angles are there in this diagram? Give a possible name for each of them.

I Do: Example 2 A The measure of an angle is usually given in degrees (later in the year we will learn that you can also measure angles in radians). A protractor is the tool used to measure angles in degrees.

We do: Example 2 B

You Do: Example 2 C

We do: Example 2 D Find the measure of each angle. Then classify each as acute, right, or obtuse. A. WXV B. YXZ C. ZXW D. YXW

Congruent angles are angles that have the same measure. Arc marks are used to show that the two angles are congruent.

In simpler words: we can add angles.

Complementary Angles (Definition) To be complementary the sum of the two angles must equal 90 degrees.

Supplementary Angles (Definition) Example 1 Example 2 To be supplementary the sum of the two angles must equal 180 degrees. The angles in example 1 are also called a linear pair.

Link to Gizmos

We Do: Example 3 B Find the value of each angle

You Do: Example 3 C Find the value of x.

We Do: Example 4 B

You Do: Example 4 C Find the value of x.

Exit Slip Given m WYZ = (2 x – 5)° m XYW = (3 x + 10)° Find the value of x.