Let ABCD be a cyclic quadrilateral wih both diagonals perpendicular to each other and intersecting at point O. Let E,F,G,H be the orthogonal projections of O on sides AB,BC,CD,DA respectively.
a. Prove that ∠EFG+∠GHE=180o
b. Prove that OE bisects angle ∠FEH . geometryperpendicularangle bisectorprojections