Generalized mirror problem
Source: Iranian second round/day1/problem1
May 2, 2019
geometryrectanglecombinatorics
Problem Statement
We have a rectangle with it sides being a mirror.A light Ray enters from one of the corners of the rectangle and after being reflected several times enters to the opposite corner it started.Prove that at some time the light Ray passed the center of rectangle(Intersection of diagonals.)