http://www.ck12.org Chapter 1. Basics of Geometry
Supplementary angles add up to 180◦. Congruent angles have the same measure. Divide 180◦by 2, to find the
measure of each angle.
180 ◦÷ 2 = 90 ◦
So, two congruent, supplementary angles are right angles, or 90◦.
Example C
Name one pair of supplementary angles in the diagram below.
One example is^6 INMand^6 MNL.
Watch this video for help with the Examples above.
MEDIA
Click image to the left for more content.CK-12 Foundation: Chapter1SupplementaryAnglesB
Vocabulary
Two angles aresupplementarywhen they add up to 180◦.
Guided Practice
Find the measure of an angle that is supplementary to^6 ABCifm^6 ABCis
- 45◦
- 118◦
- 32◦
4.x◦
Answers:
- 135◦
- 62◦
- 148◦
- 180−x◦
Practice
Find the measure of an angle that is supplementary to^6 ABCifm^6 ABCis: