Identify supplementary angles

Supplementary angles are two angles whose measures add to $180^\circ$ , whether they are adjacent or separate; when adjacent, their noncommon sides form a straight angle, creating a linear pair. Identifying supplementary pairs from diagrams or given measures, including distinguishing them from complementary angles, supports solving angle relationships with simple equations; more advanced generalizations beyond degree measures and basic geometric configurations are not included.

Detailed Explanation: Identify supplementary angles

Two angles are supplementary if their measures add to $(180^\circ)$ :

m\angle A+m\angle B=180^\circ

They may be next to each other, or they may be separate. If they are adjacent and their outside sides form a straight line, they are called a linear pair.

Example:
In a diagram, $(m\angle 1=65^\circ)$ and $(m\angle 2=115^\circ)$ . Are $\angle 1$ and $\angle 2$ supplementary?

Step 1: Add the angle measures.

65^\circ+115^\circ=180^\circ

Step 2: Compare the sum with $(180^\circ)$ .

The sum is $(180^\circ)$ , so the angles are supplementary.

Answer: $\angle 1$ and $\angle 2$ are supplementary angles. If they share a side and form a straight line, they also make a linear pair.

Remember: angles that add to $(90^\circ)$ are complementary, not supplementary.

Learn by doing: Identify supplementary angles

Click a topic below to practice the foundational skills you'll need, learn the steps, or master this skill

Practice with unlimited practice problems

Angles - Complementary, Supplementary, Opposite, Corresponding - Image to Name

Earned ?

Identify supplementary angles

Detailed Explanation: Identify supplementary angles

Learn by doing: Identify supplementary angles

Practice with unlimited practice problems

Practice:

Angles - Complementary, Supplementary, Opposite, Corresponding - Image to Name