MathDB
a square is cut into 100 rectangles by 9 + 9 lines parallel to it's sided

Source: Tournament Of Towns Spring 1999 Junior 0 Level p5

May 7, 2020
geometryrectangleSquaressquarecombinatorial geometrycombinatorics

Problem Statement

A square is cut into 100100 rectangles by 99 straight lines parallel to one of the sides and 99 lines parallel to another. If exactly 99 of the rectangles are actually squares, prove that at least two of these 99 squares are of the same size .
(V Proizvolov)