2003 Cayley Problem 13

In the diagram, ABCD is a square with a side length of 10. If AY = CX = 8, the area of the shaded region is

\textbf{(A)}\ 16\quad \textbf{(B)}\ 20\quad \textbf{(C)}\ 40\quad \textbf{(D)}\ 48\quad \textbf{(E)}\ 24

If there are no answer choices shown, enter a numerical answer.

Full credit to this problem is given to the CEMC, you may view all Cayley contests here.