MathDB
3 disks contain vertices of an equilateral triangle

Source: Romanian TST 2002

February 5, 2011
geometry proposedgeometry

Problem Statement

Find the least positive real number rr with the following property:
Whatever four disks are considered, each with centre on the edges of a unit square and the sum of their radii equals rr, there exists an equilateral triangle which has its edges in three of the disks.
Radu Gologan