In problem D. Rectangle and Square (http://mirror.codeforces.com/problemset/problem/136/D), for four co-planar points, to make a rectangle, I checked if the two shorter sides are equal, the two longer sides are equal, the diagonals are equal and the shorter side, longer side and the diagonal make a Pythagorean triangle, but my solution wasn't accepted. Is this sufficient condition for four points to make a rectangle? My solution id is 993121.