Adjustable carpenter square

An adjustable carpenter square used for finding the relative angles from a given point comprises a pair of longitudinally extending arms pivoted together in overlapping relationship at one end, a locking support ring movably positioned between said longitudinal arms, said locking support ring having a locking stud extending therefrom with means on said locking stud for engaging one of said longitudinally extending arms, means for positioning said locking ring between said longitudinally extending arms, a degree ring secured to one of said longitudinally extending arms in overlying relationship to said locking support ring, means for positioning said longitudinally extending arms in predetermined fixed position, said positions corresponding to a given relative angle therebetween expressed in degrees.