2-colouring of S yields (at least) three monochromatic collinear points
Source: IMAR 2012 p4
September 27, 2018
combinatorial geometryColoringgeometry
Problem Statement
Design a planar finite non-empty set satisfying the following two conditions:
(a) every line meets in at most four points; and
(b) every -colouring of - that is, each point of is coloured one of two colours - yields (at least) three monochromatic collinear points.