MathDB
Problem 1, Geometric Inequality

Source: Danube Contest 2016, Romania

October 29, 2017
geometric inequalityinequalities

Problem Statement

1.Let ABCABC be a triangle, DD the foot of the altitude from AA and MM the midpoint of the side BCBC. Let SS be a point on the closed segment DMDM and let P,QP, Q the projections of SS on the lines ABAB and ACAC respectively. Prove that the length of the segment PQPQ does not exceed one quarter the perimeter of the triangle ABCABC.