This final project discusses the constancy of Haruki’s entry on the ellipse. Given two nonintersecting chords AB and CD on the ellipse and a point P on the arc AB remote from points C and D, let E and F be the intersections of chords PC,AB and PD,AB respectively. The value of AE · BF/EF does not depend on the position of P. The proof is presented by geometric transformations, using the …