o see what is going on, we simply draw a triangle. Since the tower is 125 feet high, but the guy wire is 20 feet from the top, the triangle is 125 - 20 = 105 feet high, then 80 feet long.
Using the pythagorean theorem, 105^2 + 80^2 = g^2
g^2 = 11025 + 6400 = 17425
g = sqrt(17425)
g = 132.0038 feet = 132 feet
Hope this helps!
