revolutions will a seventh disk around 6 equal ones
Source: Polish MO second round 1958 p2
August 29, 2024
geometrycombinatoricscombinatorial geometry
Problem Statement
Six equal disks are placed on a plane so that their centers lie at the vertices of a regular hexagon with sides equal to the diameter of the disks. How many revolutions will a seventh disk of the same size make when rolling in the same plane externally over the disks before returning to its initial position?