Finding Missing Angles
9th Grade · Math · 45 min
Lesson Preview
Learning Objective
I can calculate the measure of an unknown angle that is supplementary to a known angle.
- 1
Supplementary angles are two or more angles that add up to 180 degrees.
- 2
If two angles are supplementary, you can set up an equation where the sum of the angles equals 180° and then solve for the unknown angle.
- 3
When parallel lines are cut by a transversal, angles on a flat line are supplementary, meaning their measures add up to 180 degrees, allowing you to solve for variables like x.
