MathDB

Let

ABCD

be a quadrilateral such that all sides have equal length and

\angle{ABC} =60^o

. Let

l

be a line passing through

D

and not intersecting the quadrilateral (except at

D

). Let

E

and

F

be the points of intersection of

l

with

AB

and

BC

respectively. Let

M

be the point of intersection of

CE

and

AF

. Prove that

CA^2 = CM \times CE

Problem Statement