Hey there!
First use pythagoras to gain the length of \(WX\)
\(WX=\sqrt{(\sqrt{13})^2-3^3}=2\)
Now we can take the tangent of \(V\)
\(tan(V)=\frac{\sqrt{(\sqrt{13})^2-3^3}}{3}=\frac{2}{3}\)
Hope this helped :)
Edit: Had \(13^2\) instead of \(\sqrt{13}^2\) oops