## Precalculus (6th Edition) Blitzer

The approximate height of the tower is $135\text{ feet}$.
Let the height of the tower be $a$. The tangent function should be applied to determine the height of the tower, \begin{align} & \tan \theta =\frac{\text{height of tower}}{\text{distance between base of tower and point of observation}} \\ & \tan 48.3{}^\circ =\frac{a}{120} \\ & a=120\tan 48.3{}^\circ \end{align} Substitute the value of $\tan 48.3{}^\circ$ in the above equation \begin{align} & a=134.6850 \\ & a\approx 135 \\ \end{align}