A square includes a laser indicator and comprises a two-part body with a channel running between them defining a pair of perpendicular arms. The channel holds a cavity for a battery or other portable power source as part of an electrical circuit. One or both arms may include a scale as well as an elongate opening on the top of the arm for a handle to move a laser/indicator back and forth along the opening. The arms preferably include a pair of bus bars to conduct electricity from the power source to the laser. The second arm may also include a laser light source that is capable of moving in a direction parallel to the arm, as well as rotating in place.