Answer
The approximate height of the tower is $135\text{ feet}$.
Work Step by Step
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
$\begin{align}
& a=134.6850 \\
& a\approx 135 \\
\end{align}$
