Question

A CB antenna is located on the top of a garage that is h = 17 feet tall. From a point on level ground that is d = 120 feet from a point directly below the antenna, the antenna subtends an angle of α = 11°, as shown in the figure. Approximate the length of the antenna.

Answer 1

got picture?

Answer 2

use tangent

\[\tan \theta = \frac{17}{120}\]
\[\theta = \tan^{-1} (\frac{17}{120})\]
then for big triangle, let x = height of antenna
\[\tan(\theta +11) = \frac{x+17}{120}\]
\[x = 120 \tan( \theta +11) - 17\]