3-2 Angles and Parallel Lines

Ms. Andrejko

Real-Life

Postulates and TheoremsPostulates

3.1 Theorems

3.13.23.33.4

ExamplesIf <2=70, find the measure of each angle:1. <3

2. <5

3. <8

70 (vertical angles)

180-70 = 110

110 (vertical to <5)

PracticeIf <2=70, find the measure of each angle:1. <1

2. <4

3. <6

180-70 = 110

110 (vertical to <4)

70

ExamplesIn the figure, m∠3 = 75 and m∠10 = 105.

Find the measure of each angle.1. <2

2. <5 3. <7

180-75 = 105

105 (vertical to <2)

105

PracticeIn the figure, m∠3 = 75 and m∠10 = 105.

Find the measure of each angle.1. <15

2. <14 3. <9

105

75

75

ExamplesFind the variables in each figure

9x+21 = 11x-122=2xx=11

11(11)-1 = 120180-120 = 605y-5=605y=65Y=13

180-60 = 1204y+4=1204y=116Y=29

3x-3=603x=63X=21

PracticeFind the variables in each figure

180-40=140140=5x28=x5(28) = 1403y-1=1403y=141y-=47

8x-10 = 7x-10=-xX=10

7(10) = 70180-70 = 1106y+20 = 1106y=90Y=15