Section 2.7

PROVE ANGLE PAIR RELATIONSHIPS

In this section…We will continue to look at 2 column

proofs

The proofs will refer to relationships with angles.

We will also use the facts about angle pairs to find measures of angles. (Algebra)

Recall these facts about angles

Right angles have a measure of 90˚Obtuse angles have angle measures greater than 90˚

and less than 180 ˚Acute angles have angle measures greater than 0 ˚

and less than 90˚Straight angles have a measure of 180˚Complementary angles are 2 angles whose sum

equals 90˚Supplementary angles are 2 angles whose sum equals

180˚Supplementary angles aren’t necessarily a linear pair

Angles cont.Perpendicular lines have an angle

measure of 90˚ Linear pairs are two angles that are supplementary

and share a common side.

Vertical pairs are angles created by two intersecting lines that are opposite each other. They also have the same angle measure.

Angles Cont.Adjacent angles are angles that share a

common interior side.Common side

“New” Theorems

Identify Congruent Pairs of Angles

<1 and <2, <1 and <3, and <2 and <3

Identify Congruent Pairs of Angles

<1 & <2, <1 & <3, <1 & <4, <2 & <3, <2 & <4, <3 & <4

Identify Congruent Pairs of Angles

<1 & <3, <4 & <2

Find the measures of the angles and the values of x and y.