Q : 3 In Fig. , , where P, Q and R are points on a circle with centre O. Find .
Construction: Join PS and RS.
PQRS is a cyclic quadrilateral.
So, PSR + PQR =
Here, POR = 2 PSR
In OPR ,
OP=OR (Radii )
ORP = OPR (the angles opposite to equal sides)
In OPR ,
OPR+ORP+POR=