In the figure,TA & TB are the tangents of the circle.C is a point on the circle.
P,Q and R are the feet of the perpendicular from C to the three sides of Triangle ABT.
a. Write down three groups of concyclic points.
b. Hence show that <CRQ=<CQP and <CQR=<CPQ
c. If QC=9cm and PC =10cm,find CR.