MathDB
odd number of grid lines , rectangle All-Russian MO 2005 Regional 10.8

Source:

August 26, 2024
combinatoricscombinatorial geometrygeometryrectangle

Problem Statement

A rectangle is drawn on checkered paper, the sides of which form angles of 45o45^o with the grid lines, and the vertices do not lie on the grid lines. Can an odd number of grid lines intersect each side of a rectangle?