#### Answer

$x \approx 28^{\circ}$

#### Work Step by Step

Since we have the measure of the side opposite to an unknown angle and the hypotenuse of the right triangle, we can use the sine ratio to find $x$, which is the measure of the unknown angle.
The sine ratio is given as follows:
sin $x = \frac{opposite}{hypotenuse}$
Let's plug in what we know:
sin $x = \frac{9}{19}$
Take the $sin^{-1}$ of the fraction to solve for $x$:
$x \approx 28^{\circ}$