Question

Given lines appearing parallel are parallel, ∠7=30°, and ∠10=80°, find the measure of the following angles.

Answer 1

<7 = 30

<7 = <5  vertical angles

<5 = <3 alternate interior angles

<3 + <2 = 180 straight line

30 + <2 = 180

<2 = 180 -30

<2 = 150

<10 = <12  vertical angles

<11 + <12 = 180

<11 + 80 = 180

<11 = 100

<7+<13+<12 = 180   it forms a triangle

30 + <13 + 80 = 180

110 +< 13 = 180

< 13 = 180-110

< 13 = 70

<13 = <15  vertical angles

< 15 = <17 alternate interior angles

< 17 = <19 vertical angles

< 19 = 70