Newsgroups:     sci.math
Subject:        A neat little theorem.
From:  (Bill Taylor)
Date:           3 Jun 92 16:15:40 +1200
Organization:   Department of Mathematics, University of Canterbury

Given any convex quadrilateral, trisect each of the sides. Join up the
corresponding points on opposite sides with straight lines (like a skewed
tictactoe board).

Prove that the central one of the nine sub-quadrilaterals, has area 
one ninth of the area of the original.


Bill Taylor