### Home > CC2 > Chapter 8 > Lesson 8.3.3 > Problem 8-90

8-90.

Find the value of each variable in the following figures. Do not use a protractor. Use the properties of angles to help you.

. Solve for .

These angles are supplementary.

and are vertical angles. What does that tell you about the measure of angle?

Set up an equation relating

and .. Subtract

from both sides.

andare complementary angles, meaning their sum is .

andare vertical angles, and andare supplementary. ,

. Refer to part (d) for the steps to solving this problem.

. Now solve for the value of .