## Precalculus (6th Edition) Blitzer

$72$ feet
We have a right angled triangle with base $90$ feet Base angle $= 38.7^{\circ}$ Now, $\tan ( 38.7^{\circ}) = \dfrac{height}{90}$ height $= 90 \times \tan ( 38.7^{\circ})$ height = $72$ feet