Solve the following math problem step by step. The last line of your response should be of the form Answer: \boxed{$Answer} where $Answer is the answer to the problem.

<image>Segments $\overline{AD}$ and $\overline{CE}$ are medians of $\triangle ACB, \overline{AD} \perp \overline{CE}, AB=10$, and $CE=9$. Find $CA$