We have the diagram:
We use the trigonometric identity cosine:
[tex]\cos\theta=\frac{adjacent}{hypotenuse}[/tex]Substitute the values:
[tex]\begin{gathered} \cos\theta=\frac{5}{16} \\ \theta=\cos^{-1}(\frac{5}{16})=71.79 \end{gathered}[/tex]Answer: 71.79°