Answer:

1:

Cos θ=12/15

θ=Cos-¹(12/15)

θ=36.87°

2:

Cos θ=x/11

x=Cos60*11

x=5.5

3:

Tan50°=x/5

x=Tan50*5

x=6

4:

Tan θ=3/3

θ=Tan-¹(1)

θ=45°