Given the Right Triangle ABC, you know that:
[tex]\begin{gathered} AB=29 \\ BC=9 \end{gathered}[/tex]In order to find the measure of the angle "x", you need to use the following Inverse Trigonometry Function:
[tex]\theta=sin^{-1}(\frac{opposite}{hypotenuse})[/tex]In this case, you can identify that:
[tex]\begin{gathered} \theta=x \\ opposite=BC=9 \\ hypotenuse=AB=29 \end{gathered}[/tex]Therefore, when you substitute values and evaluate, you get:
[tex]x=sin^{-1}(\frac{9}{29})[/tex][tex]x\approx18\text{\degree}[/tex]Hence, the answer is:
[tex]x\approx18\text{\degree}[/tex]