MathDB
mexico 1999

Source:

November 18, 2006
calculusintegrationcombinatorics unsolvedcombinatorics

Problem Statement

A polygon has each side integral and each pair of adjacent sides perpendicular (it is not necessarily convex). Show that if it can be covered by non-overlapping 2x12 x 1 dominos, then at least one of its sides has even length.