MathDB
golden ratio and pentagons: the flavor of ISL 2002 G5

Source: Moldova 2007 IMO-BMO TST II problem 4

March 23, 2007
ratiogeometrycombinatorial geometrygeometry proposed

Problem Statement

Consider five points in the plane, no three collinear. The convex hull of this points has area SS. Prove that there exist three points of them that form a triangle with area at most 5510S\frac{5-\sqrt 5}{10}S