(a) \( \ \ \) Show that \( \angle DSR = \angle DAR \). The quadrilateral \( DRAS \) is cyclic, since \( \angle DRA + \angle DSA = \pi (180^{\circ}) \). Therefore \( \angle DSR = \angle DAR \) (angles in the same segment of circle \( DRAS \), both standing on same chord […]
