any suggestions on how to solve this? thanks

Answer: x = 4
Step-by-step explanation:
You basically want to solve for the angle A. Do arcsin of 1/3, which is approximately 19.47 degrees. In this triangle, we are missing the adjacent and opposite, but we do have the angle luckily. Lets use SOH-CAH-TOA.
[tex]sin(theta) = \frac{opposite}{hypotenuse}[/tex]
We can see here that doing sine will give us the length of the opposite
[tex]sin19.47 = \frac{x}{12}[/tex]. Do sine of 19.47, then multiply by 12. I got 4