Problem
of the
Week

PROBLEM 258

Three spheres of radius one are placed on a table with each touching the other two, one additional sphere of the same size is stacked on top, as sketched on the left.  What is the radius of the largest sphere that can be placed in the hollow spot between the four spheres?

You are visitor number  2655   to this page.
ã2007 Alberto L. Delgado