Begin with an arbitrary, convex quadrilateral. Next, draw squares outwardly on the sides of the quadrilateral, and join the centers of opposite squares.

You might find the the two resulting lines are equal in length and intersect at precisely 90 degrees.

Prove (or disprove) the notion, that this is always true.

Sorry. Did not know that HTML did not work here

as it does when summitting a problem. It would

have been the same as that linked to by Federico.

Edited on July 24, 2004, 3:05 am

Posted by Bractals on 2004-07-24 02:50:08