Geometry
(Video)
If the measure of two angles added together equals 90o, the angles are complementary. A supplementary angle is formed when the sum of the measures of two angles equals 180o.
These resources are part of KET's Measurement and Geometry collection.
This video segment originally appeared in KET’s GED Connection series.
An angle is formed when two portions of a line share a common endpoint, or vertex. Angles are measured in degrees. The symbol for degrees is o. When the sum of two angles is 90o, the angles are called complementary angles. When the sum of two angles is 180o, they are called supplementary angles. An understanding of complementary and supplementary angles will help you to solve for an unknown angle measurement in geometry.
To help learners remember the difference between complementary and supplementary angles, point out that “c” comes before “s” in the alphabet, just as “90” comes before “180.”
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