MathDB

5

Part of 1997 Spain Mathematical Olympiad

Problems(1)

sum of lengths of sides and diagonals >= 2(2+\sqrt2), when (ABCD)=1

Source: Spanish Mathematical Olympiad 1997 P5

7/31/2018
Prove that in every convex quadrilateral of area 11, the sum of the lengths of the sides and diagonals is not smaller than 2(2+2)2(2+\sqrt2).
geometrygeometric inequalityconvex quadrilateral