square inscribed in triangle, sum of reciprocals of 3 inradii
Source: 2020 Dürer Math Competition Finals Day2 E13 https://artofproblemsolving.com/community/c1622639_2020_
January 7, 2022
squaregeometryinscribedinradius
Problem Statement
In triangle we inscribe a square such that one of the sides of the square lies on the side , and the other two vertices lie on sides and . Furthermore we know that , and . This square cuts out three smaller triangles from . Express the sum of reciprocals of the inradii of these three small triangles as a fraction in lowest terms (i.e. with and coprime). What is ?