Complementaryand

Supplementary Angles

DefinitionsComplementary Angles: pair of angles whose measures add to 90°.

30° & 60° 45° & 45°

Supplementary Angles: pair of angles whose measures add to 180°.

120° & 60° 100° & 80°

Draw a red circle around a set of complementary angles and a blue circle around a set of supplementary angles.

20°

40°

50°

101°

79°30°

30°

30°

125°

65°

45°

23°

41°

60°

39°10°

55°15°

70.5°

21.5° 35°

19.5°

93° 20.5°

158.5°23.8°

66.2° 19.1° 100°

89°

Have a different student come and use a red and blue square. Then another use a red and blue oval.

Now come forward (or use the slate) to measure the angles below until you finda set of complementary angles. Use the built in protractor. Then mark theangle with its measure. Once you find a set, highlight the angles.

Now come forward (or use the slate) to measure the angles below until you finda set of supplementary angles. Use the built in protractor. Then mark theangle with its measure. Once you find a set, highlight the angles.

Find sets of complementary and supplementary angles in this picture. Use the red pen to mark the set of complementary angles and the yellow pen to mark the set of supplementary angles.

Find sets of complementary and supplementary angles in this picture. Use the red pen to mark the set of complementary angles and the yellow pen to mark the set of supplementary angles.

Use your ACTIVote controller to respond to the following questions.

Which of the following is NOT a set of complementary angles?

A) 45° & 45°

B) 30° & 30° & 30°

C) 15.5° & 74.5°

D) 10° & 80°

A pair of angles can be both supplementary and complementary.

A) True

B) False

The first of two angles has a measure of 65°. Which of the following angles would be its supplement?

A) B)

C) D)