In recreational mathematics, a polydrafter is a polyform with a triangle as the base form. The triangle has angles of 30°, 60° and 90°, like a drafting triangle—hence the name. The polydrafter was invented by Christopher Monckton, whose Eternity Puzzle was composed of 209 hexadrafters. The term polydrafter was coined by Ed Pegg, Jr. The 14 tridrafters — all possible clusters of three drafters — make an excellent small puzzle that is surprisingly difficult to solve by hand.