Circles C1 and C2 with centers at C1 and C2 respectively, intersect at two points A and B. Points P and Q are varying points on C1 and C2, respectively, such that P, Q and B are collinear and B is always between P and Q. Let lines PC1 and QC2 intersect at R, let I be the incenter of ΔPQR, and let S be the circumcenter of ΔPIQ. Show that as P and Q vary, S traces the arc of a circle whose center is concyclic with A, C1 and C2. geometrySpiral SimilarityAngle ChasingLocus problemsincentercircumcircle