2) Determine x, y ez nos paralelogramos ao lado.​

A) x = z e y = 122 graus

y + x = 180 graus

122 + x = 180

x = 180 – 122

x = 58 graus

z = 58 graus

B) y = z e x = 31 graus

y + x = 180 graus

y + 31 = 180

y = 180 – 31

y = 149 graus

z = 149 graus

C) x = y e z = 23 graus

x + z = 180 graus

x + 23 = 180

x = 180 – 23

x = 157 graus

y = 157 graus

D) (3y – 11 graus) = 130 graus

(2x + 12 graus) + 130 graus = 180 graus

(3y – 11) = 130

3y = 130 + 11

3y = 141

y = 141/3

y = 47

(2x + 12) + 130 = 180

2x + 142 = 180

2x = 180 – 142

2x = 38

x = 38/2

x = 19 graus

E) 2x + y = 77 graus

5x – 7 graus + 77 graus = 180 graus

5x – 7 + 77 = 180

5x + 70 = 180

5x = 180 – 70

5x = 110

x = 110/5

x = 22 graus

2x + y = 77 graus

2 . 22 + y = 77

44 + y = 77

y = 77 – 44

y = 33 graus

F) 2y – 1 grau + 10 y + 1 grau = 180 graus

12y = 180

y = 180/12

y = 15 graus

2x + y = 2y – 1 grau

2x = 2y – y – 1

2x = y – 1

2x = 15 – 1

2x = 14

x = 14/2

x = 7 graus