Chapter 12.1, Problem 1E

To determine

To State: The name of the relationship between two angles when the sum of their measures is ${90}^o$ .

Answer to Problem 1E

The sum of the measures of two complementary angles is ${90}^o$ .

Explanation of Solution

Two angles are called complementary if the sum of their measures is ${90}^o$ and they are called supplementary of the sum of their measures is ${180}^o$ .

In other words, it can also be stated that adjacent angles that form a right angle are complementary and adjacent angles that form a straight angle are supplementary.

Therefore, the sum of the measures of two complementary angles is ${90}^o$ .