The measure of an angle is 4y. Find the measure of its complement.

A) 90 - 4y

B) 90 + 4y

C) 180 - 4y

D) 180 + 4y

Complementary angles are angles whose measure add up to 90°.

So, if one angle is 4y, the complementary angle is 90° - 4y. Choice A.

Complementary angles does not necessarily need to share a line or vertex. As long as both angles have a sum of 90°, then, they are complementary angles.

Angles who has a sum of 180° are called supplementary angles.