The length of ladder is L = 42 foot.
The distance between base of building and ladder is b = 8.5.
Determine the measure of angle by using the trigonometry.
[tex]\begin{gathered} \cos \theta=\frac{8.5}{42} \\ \theta=\cos ^{-1}(0.20238) \\ =78.323 \\ \approx78.3 \end{gathered}[/tex]So measure of angle is 78.3 degree.
