MathDB
geometrical inequality involving the centroid

Source: bmo 1989

April 23, 2007
inequalitiesgeometry proposedgeometry

Problem Statement

Let GG be the centroid of a triangle ABCABC and let dd be a line that intersects ABAB and ACAC at B1B_{1} and C1C_{1}, respectively, such that the points AA and GG are not separated by dd. Prove that: [BB1GC1]+[CC1GB1]49[ABC][BB_{1}GC_{1}]+[CC_{1}GB_{1}] \geq \frac{4}{9}[ABC].