AMC 12 2012a Problem 10

A triangle has area $30$, one side of length $10$, and the median to that side of length $9$. Let $\theta$ be the acute angle formed by that side and the median. What is $\sin{\theta}$?

\textbf{(A)}\ \frac{3}{10} \textbf{(B)}\ \frac{1}{3} \textbf{(C)}\ \frac{9}{20} \textbf{(D)}\ \frac{2}{3} \textbf{(E)}\ \frac{9}{10}