Answer
$\approx 14.4$
Work Step by Step
The Trigonometric ratios for $tangent$ function can be written as follows:
$\ Tan \theta=\dfrac{Opposite}{Adjacent}$
We are given that the length of Adjacent and the angle. Our aim is to compute the side of opposite to the angle.
Therefore, $\tan 64^{\circ}=\dfrac{x}{7}$
This implies that $x= 7 \tan 64^{\circ} \approx 14.4$
