Angles

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

Possible Names for this angle: An angle has two sides than meet a the vertex. In the angle below the sides are 𝑅𝑆 and 𝑅𝑇. These two sides intersect a the vertex of the angle which is point R. Possible Names for this angle: 1 R SRT TRS

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

I Do: Example 2A 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 2B

You Do: Example 2C

We do: Example 2D 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 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

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

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

We Do: Example 4B

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

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