Answer:
[tex]x=18[/tex]
Step-by-step explanation:
In any right triangle, the sine of an angle is equal to the angle's opposite side divided by the hypotenuse.
Therefore, we have the following equation:
[tex]\sin 30^{\circ}=\frac{9}{x},\\\frac{1}{2}=\frac{9}{x},\\x=9\cdot 2=\boxed{18}[/tex]
*Note that [tex]\sin 30^{\circ}=\frac{1}{2}[/tex]
