Supplementary Angles

Definition: Supplementary angles are two angles whose measure have a sum of 180°.


Example: Find the measure of angle x that would make the pair of angles supplementary.



Use the information from the figure to find the value of angle x.

Step 1: We know a pair of supplementary angles has a sum of 180°. Here our given angles measure 130° and x°. Using this information, write an equation that will allow us to solve for x.

130 + x = 180

Step 2: Solve for x:

130 + x = 180
x = 180 – 130
x = 50°

When angle x = 50°, the angles are supplementary.

Still need help solving complementary angles? Download Yup and get help from an expert math tutor 24/7.