TOT 104 1985 Autumn S1 PA+PB+PC+PD <=L+D_1+D_2
Source:
August 26, 2019
convexdiagonalSumperimetergeometric inequality
Problem Statement
We are given a convex quadrilateral and point inside it . The perimeter of the quadrilateral has length while the lengths of the diagonals are and . Prove that the sum of the distances from to the vertices of the quadrilateral are not greater than .(V. Prasolov)