"The rig consists of a triangular sail set aft of the mast with its head raised to the top of the mast; its luff runs down the mast and is normally attached to it for its entire length; its tack is attached at the base of the mast; its foot (in modern versions of the rig) controlled by a boom; and its clew attached to the aft end of the boom, which is controlled by its sheet."

https://en.wikipedia.org/wiki/Bermuda_rig