MMO 031 Moscow MO 1936 3 planes and a ball in space, ways
Source:
July 18, 2019
combinatorial geometrycombinatoricsgeometry3D geometry
Problem Statement
Given three planes and a ball in space. In space, find the number of different ways of placing another ball so that it would be tangent the three given planes and the given ball. It is assumed that the balls can only touch externally.