16 checkers are placed on an 8 by 8 checkerboard, no two checkers on the same square. Show that some four of the 16 checkers are on the vertices of a parallelogram with positive area.

(In reply to oops by KC)

Right.  Could you try your hand at "Special Similar Set" by Old Original Oskar!?  I'm curious if there is a solution for part 2 different from mine.

Posted by McWorter on 2005-07-31 22:37:28