Ienquality involving sides a,b,c and angles α, β, γ
Source: Baltic Way 1994
December 22, 2011
geometry unsolvedgeometryInequality
Problem Statement
Let α,β,γ be the angles of a triangle opposite to its sides with lengths a,b,c respectively. Prove the inequality
a(β1+γ1)+b(γ1+α1)+c(α1+β1)≥2(αa+βb+γc)