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Longest line to cut a square into a 20:23 ratio

Source: Indonesia Regional 2023 Essay Number 1

July 16, 2023
geometryratioIndonesiaareaRMO

Problem Statement

Let ABCDABCD be a square with side length 4343 and points XX and YY lies on sides ADAD and BCBC respectively such that the ratio of the area of ABYXABYX to the area of CDXYCDXY is 20:2320 : 23 . Find the maximum possible length of XYXY.