by Bailey Jo
Teachers, take heed: this is a very clean, ideal example of a tessellation that repeats via the translation (slide) method and the glide-reflection (flip) method. In the Heesch system, Bailey Jo's tessellation is called type TG1G2TG2G1. In zoology, this kind of tessellation is called "too many gorillas and not enough room".
Bailey Jo used the tracing paper method, my favorite, to make this tessellation.
None of this jargon-rich blather answers the biggest question: "Why do these gorillas look so nervous?" Anything that worries a pack of 800 pound gorillas should worry us, too.
Somebody, go warn Bailey Jo.