# What are supplementary and complementary angles? And how do I find the complement and supplement of an angle measure?

Dec 7, 2015

Two angles that add up to either 180 (supplementary) or 90 (complementary)

#### Explanation:

Note: I will be using the asterisk as a degrees sign.

A Supplementary Angle is and an angle that measure 180 (aka a stragight line) and a Complementary Angle is an angle that measures 90 (aka a right angle). When it says angleS it means the 2 or more angles that add up to either 180 (supplementary) or 90 (complementary).

For example, if a question asks "What is the Complement of an angle that measures 34?" we would take 90 (because complementary means 90 angle) and subtract 34 from it to find its complement which is a 56 angle. A Complement is an angle that when added with a given angle adds up to 90. The equation for this would be $90 = \angle 1 + \angle 2$.

If a question asks "What is the Supplement of an angle that measures 92?" we would take 1800 (because supplementary means a 180 angle) and subtract 92 from it to find its supplement which is a 88 angle. A Supplement is an angle that when added with a given angle adds up to 180. The equation for this would be $180 = \angle 1 + \angle 2$.

For both scenarios, there can be multiple angles that add up to either 180 or 90 in which case you would just call them supplementary or complementary when they are referenced together. In an equation you would just add the other angle measures in to either equation accordingly.