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
complementary angles
Nonadjacent
complementary angles
Adjacent
supplementary angles
Nonadjacent
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. 4
Two 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
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