Which of the following statements is true? a. adjacent angles are always complementary. b. the sum of the measures of complementary angles equals 90°. c. adjacent angles are always equal in measure. d. the sum of the measures of supplementary angles equals 90°.

B

Step-by-step explanation:

We have to find the true statements

A. Adjacent angles are always complementary.

It is not true. Because it is not necessary that sum of adjacent angle is always equal to 90 degrees.

B.The sum of the measures of complementary angles equals 90 degrees.

We know that complementary angle:The pair of angles whose sum is equal to 90 degrees is called complementary angles.

Hence, option B is true.

C.Adjacent angles are always equal in measure.

It is not true.Because it is not necessary that adjacent angles are always equal in measure.

D.The sum of the measures of supplementary angles equals 90 degrees.

It is not true because sum of supplementary angles equals to 180 degrees not 90 degrees.

B