Matrices And Determinants

109. If $A, B, C$ are the angles of a $\triangle A B C$, then

$$ \Delta=\left|\begin{array}{ccc} \sin 2 A & \sin C & \sin B \\ \sin C & \sin 2 B & \sin A \\ \sin B & \sin A & \sin 2 C \end{array}\right| \text { is equal to } $$