Mimimum radius of three semicircles in rectangle
Source: 2023 Israel National Olympiad P5
December 16, 2022
geometrygeometric inequalityrectangle
Problem Statement
Let be an equilateral triangle whose sides have length . The midpoints of are respectively. Points were chosen on so that is a rectangle. Inside this rectangle are three semi-circles with the same radius, as in the picture (the endpoints are on the edges of the rectangle, and the arcs are tangent).
Find the minimum possible value of the radii of the semi-circles.