periaktoi (περίακτοι)
(Greek; sing. periaktos: from Greek, revolving; three-sided, revolving scenic device for quickly changing the scene).
Greek sing. periaktos from Greek revolving three-sided revolving scenic device for quickly changing the scene. This was a device for changing scenery by mounting three upright painted flats on a triangular base. By rotating the unit three different painted looks could be revealed to the audience. Used for quickly changing scenic backgrounds.""
14 BC
A periaktos is a triangular wooden structure to quickly change scenes and create the illusion of depth on stage. Each of the three sides had a different scene painted on it, so by revolving the periaktos the scene could be changed within seconds.