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Complementary and supplementary angles review

Review the basics of complementary and supplementary angles, and try some practice problems.

Complementary angles

Complementary angles are two angles with a sum of 90. A common case is when they form a right angle.

Supplementary angles

Supplementary angles are two angles with a sum of 180. A common case is when they lie on the same side of a straight line.
Want to learn more about complementary and supplementary angles? Check out this video.

Practice set 1: Identify complementary and supplementary angles

Problem 1A
What is the relationship between AXY and YXB?
All segments that appear straight are straight.
Choose 1 answer:

Want to try more problems like this? Check out this exercise.

Practice set 2: Find a missing angle measure

Problem 2A
If AOC is a right angle and mAOB=79, what is mBOC?
Note: Angles not necessarily drawn to scale.
  • Your answer should be
  • an integer, like 6
  • a simplified proper fraction, like 3/5
  • a simplified improper fraction, like 7/4
  • a mixed number, like 1 3/4
  • an exact decimal, like 0.75
  • a multiple of pi, like 12 pi or 2/3 pi

Want to try more problems like this? Check out this exercise.

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