1997 Fermat Problem 12

On a circle, ten points A_1, A_2, A_3, ..., A_{10} are equally spaced. If C is the centre of the circle, what is the size, in degrees, of the angle A_1A_5C?

\textbf{(A)}\ 18\quad \textbf{(B)}\ 36\quad \textbf{(C)}\ 10\quad \textbf{(D)}\ 72\quad \textbf{(E)}\ 144

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 Fermat contests here.