From the top \( A \) of a vertical wall \( AB \) of height \( 30 \, \text{m} \), the angles of depression of the top \( P \) and bottom \( Q \) of a vertical tower \( PQ \) are \( 15^\circ \) and \( 60^\circ \) respectively. \( B \) and \( Q \) are on the same horizontal level. If \( C \) is a point on \( AB \) such that \( CB = PQ \), then the area (in \( \text{m}^2 \)) of the quadrilateral \( BCPQ \) is equal to:
