A periaktoi is a kind of a device which is used in a theatre where plays, dramas and musicals are held. This device helps in changing theatre scenes at a rapid speed. This device was invented back in the first century in Greece. Periaktoi when loosely translated to Greek means 'to revolve'. These devices were famously used in and after the Renaissance period. The scenes are painted on revolving wheels in a shape of a triangle. When the scene ends, it is immediately revolved to change the scene. You can make up to three scenes on one periaktoi. Amazing illusions can also be created with its help.