To find theta first we can use the trigonometric identity of tangent thet say:
[tex]\tan (\theta)=\frac{oposite}{adyacent}[/tex]So we replace for our triangle so:
[tex]\begin{gathered} \tan (\theta)=\frac{11}{13}=0.846 \\ \theta=tan^{-1}(0.846) \\ \theta=40.2 \end{gathered}[/tex]