Loving the Circles

Two circles having radii $r_1$ and $r_2$ passing through vertex $A$ of a triangle $ABC$ . One of the circle touches the side $BC$ at $B$ and other circle touches the side $BC$ at $C$ . If $a = 5$ and $\angle BAC = 30^\circ$ , find $\sqrt{r_1 r_2}$ .