If two parallel lines XX' and YY' are intersected by a transversal, and the interior angles on the same side of the transversal are given as (13a + 10)° and (21a + 10)°, find the value of a.

If B is the center of a circle and lines AD and CD are tangent segments drawn from an external point D, then which of the following classifications apply to quadrilateral ABCD? (a) Kite (b) Cyclic quadrilateral (c) Rhombus (d) Trapezium

In a parallelogram PQRS, rays PA and SA are the angle bisectors of ∠QPS and ∠RSP respectively. Find the measure of ∠PAS.