Let T be a point of contact of a tangent drawn from an external point P to a circle with centre O. The second tangent from P touches the circle at S. The points T and S are joined to form chord TS, and O is joined to T and S.
(a) Prove that △OTP≅△OSP.
(b) Deduce that OT=OS and ∠TOP=∠POS.
(c) Prove that quadrilateral TOSP is cyclic.
(d) If the radius of the circle is r and ∠TOS=θ, express the area of △TPS in terms of r and θ.