MathDB

4

Part of 2000 Baltic Way

Problems(1)

Triangle with A = 120

Source: Baltic Way 2000 Problem 4

2/13/2009
Given a triangle ABC ABC with \angle A \equal{} 120^{\circ}. The points K K and L L lie on the sides AB AB and AC AC, respectively. Let BKP BKP and CLQ CLQ be equilateral triangles constructed outside the triangle ABC ABC. Prove that PQ \ge\frac{\sqrt 3}{2}\left(AB \plus{} AC\right).
geometryparallelogramgeometry unsolved