3-2 Angles and Parallel Lines

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3-2 Angles and Parallel Lines Ms. Andrejko

Real-Life

Postulates and Theorems 3.1 Theorems 3.2 3.3 3.4

Examples If <2=70, find the measure of each angle: 1. <3 2. <5 3. <8 70 (vertical angles) 180-70 = 110 110 (vertical to <5)

Practice If <2=70, find the measure of each angle: 1. <1 2. <4 3. <6 180-70 = 110 110 (vertical to <4) 70

Examples In 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

Practice In the figure, m∠3 = 75 and m∠10 = 105. Find the measure of each angle. 1. <15 2. <14 3. <9 105 75 75

Examples Find the variables in each figure 11(11)-1 = 120 180-120 = 60 5y-5=60 5y=65 Y=13 3x-3=60 3x=63 X=21 180-60 = 120 4y+4=120 4y=116 Y=29 9x+21 = 11x-1 22=2x x=11

Practice Find the variables in each figure 180-40=140 140=5x 28=x 5(28) = 140 3y-1=140 3y=141 y-=47 8x-10 = 7x -10=-x X=10 7(10) = 70 180-70 = 110 6y+20 = 110 6y=90 Y=15