What exactly do you mean by geometric interpretation? Is it something like writing the above equation in the form of a geometrically meaningful statement?
Geometrically it's an equation which links the sides of a parallelogram to its diagonals : $\displaystyle OC^2+OE^2=2(OA^2+AC^2)=\frac{1}{2}(OD^2+EC^2)$
Last edited by flyingsquirrel; Jul 2nd 2008 at 03:23 AM.
Reason: OD^2 = 4OA^2 != 2OA^2 :(