To begin we need to find the value of a
We apply the Pythagorean theorem
[tex]\begin{gathered} 18^2=a^2+10^2 \\ a^2=18^2-10^2 \\ a=\sqrt{18^2-10^2} \\ a=4\sqrt{14} \end{gathered}[/tex]
Now we find theta
Here we use the tangent that is the oppositive side over the adjacent side
[tex]\begin{gathered} \tan\theta=\frac{4\sqrt{14}}{33} \\ \\ \theta=\tan^{-1}(\frac{414}{33})=24.39\degree \end{gathered}[/tex]
