Out of two concentric circles, the radius of the outer circle is 5 cm. A chord of the outer circle of length 8 cm is tangent to the inner circle. What is the radius of the inner circle (in cm)?

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.