Answer:
angle = 85 degrees 
height = 637 meters
Explanation:
pythagorean theorem 
a^2 + b^2 = c^2 
53.5^2 + b^2 = 639.4^2 
2862.25 + b^2 = 408832.36 
408832.36 - 2862.25 = 405970.11 
b^2 = 405970.11 

b = 637.15 
b = 637.2 
so the height of the antenna is approximately 637.2 meters 
to find the angle we will use trigonometric ratios 
tan x = opposite/adjacent 
plug in our values 
tanx = 637/53.5
tanx = 11.91
arctan (11.91) = 85.2