Geometry Ch. 1

1.6 Angle Pair Relationships

Two angles are complementary angles if the sum of their measures is 90°. Each angle is the complement of the other.

Two angles are supplementary angles if the sum of their measures is 180°.

Complementary angles and supplementary angles can be adjacent angles or nonadjacent angles. Adjacent angles are two angles that share a common vertex and side, but have no common interior points.

Adjacent Nonadjacent complementary angles complementary angles

Adjacent Nonadjacentsupplementary angles supplementary angles

Ex. 1: Using the figure below, name a pair of complementary angles, a pair of supplementary angles, and a pair of adjacent angles.

Ex. 2

ANGLE PAIRS—Two adjacent angles are a linear pair if their noncommon sides are opposite rays. The angles in a linear pair are supplementary angles.

Two angles are vertical angles if their sides form two pairs of opposite rays.

Angle 3 and angle 1 are vertical angles.Ex. 3.a)What is an adjacent angle to angle 3? b) What is the measure of angle 3?

Ex. 4Two angles form a linear pair. The

measure of one angle is eight times the measure of the other. Find the measure of each angle.

What is the first step? Why?

Ex. 4. (cont.)8x + x = 180°9x =180°x =20° 8 (20°)=160° The measure of one angle is 20°, and the

measure of the other angle is 160°.

Websites used in preparation for this PPT:

www.seal-pa.org www.mathleague.com http://www.pinkmonkey.com/studyguides/subjects/geometry/chap1/Image434.gif

http://math247.pbwiki.com/f/6mg2.2.gif http://www.google.com/imgres?imgurl=http://education.yahoo.com/homework_help/math_help/solutionimages/miniprealggt/7/1/1/miniprealggt_7_1_1_7_70/f-452-3-pr-q.gif&imgrefurl=http://education.yahoo.com/homework_help/math_help/problem%3Fid%3Dminiprealggt_7_1_1_7_70&h=300&w=300&sz=1&tbnid=gdnCOqLtam8J::&tbnh=116&tbnw=116&prev=/images%3Fq%3Dvertical%2Bangles&sa=X&oi=image_result&resnum=3&ct=image&cd=1

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wikipedia/commons/thumb/8/8f/Simple_polygon.svg/588px-Simple_polygon.svg.png&imgrefurl=http://commons.wikimedia.org/wiki/Image:Simple_polygon.svg&h=521&w=588&sz=14&hl=en&start=16&um=1&tbnid=chzcOy4W_qR_lM:&tbnh=120&tbnw=135&prev=/images%3Fq%3Dpolygon%26um%3D1%26hl%3Den%26client%3Dfirefox-a%26rls%3Dorg.mozilla:en-US:official%26sa%3DG

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