Answer :
Given data:
The given height of the building is H=45 ft.
The given distance is D=85 ft.
The expression for the angle of elevation is,
[tex]\begin{gathered} \tan \theta=\frac{H}{D} \\ \theta=\tan ^{-1}(\frac{45}{85}) \\ =27.9^{\circ} \end{gathered}[/tex]Thus, the angle of elevation is 27.9 degrees.