There are two large mirrors standing upright and facing each other, both 10 meters long. They are not quite parallel: if you extended them, they would intersect at a $1^\circ$ angle. The distance from the mirrors to this intersection point is also 10 meters. See below (the angle in the picture is exaggerated to make it more readable). ![enter image description here][1] You also have a laser gun, which you plan to shoot at one of the mirrors so that the beam ricochets back and forth between them as many times as possible. > What's the greatest number of reflections you can get? Assume that a laser will reflect even if it hits the very edge of a mirror. *Source:* [MSRI Emissary, Spring 2002, Puzzle Section](https://www.msri.org/attachments/media/news/emissary/EmissarySpring02.pdf) [1]: https://i.sstatic.net/aVV78.jpg