Two circles with centers X and Y have radii 37 cm and r cm respectively. They intersect each other at points A and B. If the common chord AB = 24 cm and the distance between their centers X and Y is 51 cm, then find the value of r.

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.