MathDB
TOT 465 1995 Autumn J O3 folding paper rectangle

Source:

July 9, 2024
geometryfoldinggeometric inequalityrectangle

Problem Statement

A paper rectangle ABCDABCD of area 11 is folded along a straight line so that CC coincides with AA. Prove that the area of the pentagon thus obtained is less than 3/43/4.