Question

The measure of an angle is 63 degrees. What is the measure of its supplement?

A. 27 degrees
B. 36 degrees
C. 117 degrees
D. 153 degrees

Answer 1

What are supplementary angles?

Answer 2

It's two angles that add up to 180 degrees.

Answer 3

Correct.
Two angles that have measures that add up to 180 degrees are supplementary angles.

One angle has measure 63 degrees. What is the measure of the other angle?
You can let the unknown angle be x.
Then, x + 63 is the sum of the measures of the two angles.
We know they are supplementary, so the sum is 180, so we get the equation:

x + 63 = 180

Do you know how to solve for x?