What is the size of angle x in the diagram

Explanation

\(Sin\theta^{\circ} = \frac{opp}{hyp}\\
Sin X^{\circ}=\frac{5}{10}=0.5000\\SinX^{\circ}\\
X^{\circ} = sin^{-1}0.5000\\
X^{\circ}=30^{\circ}\)