Question 616658
I assume you have the diagram, so you see that the antenna and the ground make a 90 degree angle. So picture it as a triangle with a vertical line of 30 ft and the 'hypotenuse' i.e. the wire, is 50 ft long. 

To find the angle you use the opposite length to the angle (i.e. the height of the tower) and the hypotenuse.

To do this you must use Sine.

If we call the angle X then the formula is:

Sin (X) = Opposite/Hypotenuse
so:

Sin (X) = 30/50

Sin (X) = 0.6

X = Sin^-1    0.6

so using the inverse sine of 0.6

X = 36.9 degrees