2010012901

Consider a circle $k$ with radius $5\mathrm{cm}$. In the circle is inscribed a convex quadrilateral $ABCD$ so that the diagonal $AC$ is the diameter of the circle, the length of $BC$ is $8\mathrm{cm}$, and the length of $DC$ is $5\mathrm{cm}$. Determine the length of side $AD$. (See the picture.)