A,B,C,D are four points on a circle with radius R such that AC is perpendicular to BD and meets BD at E. prove that:EA2+EB2+EC2+ED2=4R2
A,B,C,D are four points on a circle with radius R such that AC is perpendicular to BD and meets BD at E. prove that:EA2+EB2+EC2+ED2=4R2