Trampoline shapes range from different rebounder models to larger circular, rectangular, square and octagon trampolines used for enjoyment and competition. Depending on the use of the equipment, trampolines can come in a variety of size. Determine your requirement according to the shape and size you require. Search online and buy from a worthy trampoline website.<br /><br />Reference: http://www.ezinearticles.biz/article/Backyard-Trampoline-is-Always-a-Great-Fun/76988<br />Images: http://www.uksportimports.com/catalog/trampolines