Question

find the total length of guy wire needed to secure both sides of a 25ft TV antenna to a flat roof there is a 30 degree angle between the Mast and the guy wires. round to nearest hundredth.

Answer 1

So we are looking at three times the hypotenuse of a right triangle with an acute angle of 30 degrees, and the longer leg 25'.
Each guy wire is therefore 25'/cos(30)=28.8675'
Most antenna have (minimum) three guy wires for stability, so total length
L=3*28.8675=866.03 m.

If the diagram shows other than 3 guy wires, multiply 28.8675 by the appropriate number accordingly.