### Home > CC2 > Chapter 9 > Lesson 9.1.1 > Problem 9-21

9-21.

Review the definitions of complementary, supplementary, and vertical angles. Use the information to answer the following questions.

Two angles are complementary. If one measures

, what is the measure of the other angle? Two angles whose measurements add up to

are called complementary. Two angles are supplementary. If one measures

, what is the measure of the other angle? Two angles whose measurements add up to

are called supplementary. Two angles are vertical. If one measures

, what is the measure of the other angle? Vertical angles have equal measures.