Given a rectangle with diagonal length d. On each side pick an arbitrary point that is not a corner.
Let u, x, y, and z be the side lengths of the convex quadrilateral determined by these four points.
d2 ≤ u2 + x2 + y2 + z2 < 2d2.
(In reply to re: Solution - your reason to edit
No, I typed it in on-line. It's always worked before.
One of life's many mysteries..
Thanks for your concern anyway.
Posted by Harry
on 2009-07-18 16:53:08