Q. 17)
Let $\triangle A B C$ be an isosceles triangle such that $A B$ and $A C$ are of equal length. $A D$ is the altitude from $A$ on $B C$ and $B E$ is the altitude from $B$ on $A C$. If $A D$ and $B E$ intersect at $O$ such that $\angle A O B=105^{\circ}$, then $\frac{A D}{B E}$ equals
- $\sin 15^{\circ}$
- $\cos 15^{\circ}$
- $2 \cos 15^{\circ}$
- $2 \sin 15^{\circ}$