Ok, so
Let me draw the triangle here below:
In this case, the most useful function we could use, is tan(x).
Tan(x) relations the opposite side of the angle and the adjacent side of the angle, like this:
tan(x) = 4/5
And, to find x, we just apply the inverse function of tan(x):
x = arctan(4/5)
x = 38.65°, which rounded to the nearest degree is 39°.
14.
Here, we have to use tan(x) again. We relation the opposite side of x and its adjacent side.
tan(x) = 9/3
tan(x) = 3
x = arctan(3)
x = 72°
15.
Here, we have to use tan(x) again. We relation the opposite side of x and its adjacent side.
This is:
tan(x) = 7/14
tan(x) = 0.5
x = arctan(0.5)
x= 26.56 which rounded to the nearest degree is 27°.