Question

What is a supplementary angle??

Answer 1

It is an angle that has a sum of a 180°

Answer 2

A single angle is generally not considered to be supplementary. Supplementary angles are angles that equal 180° when they are added together. For example, 70° and 110° are supplementary because they equal 180°.

However, I guess the supplementary angle can be the angle that must be added to another to total 180°. For example, 80° is the supplementary angle of 100°.