Download Section 1.5-Describe Angle Pair Relationships

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Classify each angle as acute, right, obtuse or
straight.
1. m ˂ DBE = 35 °
2. m ˂ EBC = 80°
3. m ˂ MPL = 90°
4. m ˂ ABD = 180 °
5. m ˂ CRF= 91 °
Geometry
1.5: Describe Angle Pair Relationships
Objective: SWBAT use special angle relationships to find
angle measures.
Angle Relationships

Complementary Angles:


Two angles whose measures have a sum of 90°
Supplementary Angles:

Two angles whose measures have a sum of 180°
Example
For each number below, Angles 1 and 2 are
complementary and angles 2 and 3 are
supplementary. Find the missing angles.
measure.
Supplementary & Complimentary
Angles Examples
Angle Relationships

Adjacent Angles:


Angles that share a common vertex and side but have
no common interior points
Linear Pair:

Two adjacent angles whose non-common sides are
opposite rays.
The sum of the measures of angles that form a linear pair is 180°
Angle Relationships

Vertical Angles:

*

Two angles whose sides form two pairs of opposite rays
vertical angles are congruent *
Perpendicular Lines:

Two lines that intersect to form a right angle.
Find angle measures in a linear pair
ALGEBRA
Two angles form a linear pair. The measure of one angle is 5
times the measure of the other. Find the measure of each angle.
SOLUTION
Let x° be the measure of one angle. The
measure of the other angle is 5x°. Then
use the fact that the angles of a linear
pair are supplementary to write an
equation.
Vertical? Linear? Neither?
Vertical Angles
Homework
Textbook Pages 39 - 40
# 10, 14, 17, 20, 22, 24, 26, 31, 40, 42