Abstract: An adjustable square device for scribing cut lines on large flat panels. The device has as a base member a straight, flat, rectangular bar. Pivotally connected at one end to the base member is an angularly adjustable pivot arm, also comprising a straight, flat, rectangular bar having an arcuate extension on one where such pivot arm is connected to the base member. The arcuate extension extends through a slot in the base member and is marked in degrees to form a quarter circle protractor integral with the pivot arm. Such protractor contains therein an arcuate groove, parallel with the outer edge of such arcuate extension and spaced inwardly therefrom. An adjustable stop extends through said groove and through the base member. The arcuate extension is pivoted on a pin affixed at the end thereof to the base member. Releasing the adjustable stop permits the pivot arm to be angled relative to the base member to the desired degree as indicated on the protractor.