Online Geometry Problems, High School, College

Online Geometry Problem 474: Parallelogram, Diagonal, Circle, Vertex

The figure shows a parallelogram ABCD and a circle C1 passing through vertex C. Circle C1 intersects sides BC and CD at points E and F, respectively, and diagonal AC at point G. Prove that CA.CG = CB.CE + CD.CF.

Problem 474: Parallelogram, Circle, Diagonal