Question 156
The three sides of an equilateral triangle are assumed to be reflective (except at the vertices), so that they reflect the rays of light located in their plane inside the triangle, which fall on them and leave an interior point of the triangle. Determine the path of a ray of light that, starting from a vertex of the triangle, reaches another vertex of the same after being successively reflected on all three sides. Calculate the length of the path followed by the light assuming that the side of the triangle measures $1~\mathrm{m}$.