To find the measure of a side in a right triangle as given (have a angle of 90º) you use the trigonometric function. Use the value of the angle W=31º
[tex]\tan \alpha=\frac{opposite}{adjacent}[/tex]The opposite side of angle W is XV and the adjacent side is y:
[tex]tan31=\frac{8.4ft}{y}[/tex]Use this equation to find the value of side WX (y):
[tex]\begin{gathered} y\cdot\tan 31=8.4ft \\ y=\frac{8.4ft}{\tan 31} \\ \\ y=13.979ft \end{gathered}[/tex]Then, side WX is 14.0 ft (rounded to the nearest tenth)