Question

A guy wire is attached to the top of a radio antenna and to a point on horizontal ground that is 40.0 meters from the base of the antenna. If the wire makes an angle of 55° with the ground, approximate the length l of the wire. (Round your answer to the nearest tenth.)

Answer 1

It is useful to start by drawing a picture to visualize this problem.

In this case we are going to use the trigonometric function cosine, which is Cos(theta) = adjacent / hypotenuse.

Cos(55) = 40 / x

After simplifying we reach the equation: X = 40 / cos(55)

which would then make the length of the wire 69.7 meters long.