Aplicando as relações trigonométricas no triângulo retângulo c...

a) sen60 = x/11

√3/2 = x/11

2x = 11√3

x = 11√3/2

x = 5,5√3

b) sen30 = x/10

1/2 = x/10

2x = 10

x=10/2

x = 5

c) cos45 = x/7

√2/2 = x/7

2x = 7√2

x = 7√2/2

x = 3,5√2

d) cos60 = 9/x

1/2 = 9/x

x = 2×9

x = 18

e) tg30 = 8/x

√3/3 = 8/x

x√3 = 3×8

x√3 = 24

x = 24/√3

x = 24√3/3

x = 8√3

f) tg60 = 13/x

√3 = 13/x

x√3 = 13

x = 13/√3

x = 13√3/3

g) cos54 = x/12

0,588 = x/12

x = 0,588×12

x = 7,056

h) tg75 = x/11

3,732 = x/11

x = 11×3,732

x = 41,052