Complementary and Complementary and Supplementary Supplementary

AnglesAngles

Complementary and Complementary and Supplementary Supplementary

AnglesAnglesSection 2.2Section 2.2

Elena de SotoElena de Soto

Complementary and Supplementary Angles

Often times we see angles that measures add up to either a right angle or a straight angle. These are Complements and Supplements.

Video on Complementary Angleshttp://youtube.com/watch?v=93gal5blsU4

Video on Supplementary Angles http://youtube.com/watch?v

=3gwcv9LSBO8

Complements• Complementary

angles are two angles whose sum is 90° (or a right angle). Each of the two angles is called the complement of the other.

Practice• Find the

complement of 58°

Answer=32°

Supplements• Supplementary

angles are two angles whose sum is 180° (or a straight angle). Each of the two angles is called the supplement of the other

Practice• Find the

supplement of 139°

Answer=41°

Sample Proof

Algebraic ProblemsAn angle and its complement add to a right angle. An angle and its supplement add to a straight angle. Since a right angle is 90 degrees and a straight angle is 180 degrees.

The complement of an angle x degrees is (90 - x) degrees.

The supplement of an angle x degrees is (180 - x) degrees.

Algebraic Formula

Find the measure of XVS

Answer=60°

More Practice Problems

For more practice problems, it is recommended to try book page 70 #12-24

Works Cited

Angles in Geometry. 25 Nov. 2007. Analyze Math. 29 May 2007 <http://www.analyzemath.com/Geometry/angles.html>.

Rhoad, Richard. Geometry for Enjoyment and Challenge. Illinois: McDougal Littell, 1991.

The Math Forum. Drexel. 29 May 2007 <http://mathforum.org/library/drmath/view/53168.html>.