PURPOSE: To expect the promptness and accuracy of formation of an angle required for civil engineering and building and the other engineering by pivoting profiling rulers on the tip of a vertical rod through a pivot, pivoting the tips of connecting rods at equal distances from the middle of the profiling rulers, and locking the base ends by set screws inserted in a slide elongated hole.

CONSTITUTION: Profiling rulers 2, 2 are pivoted on the tip of a vertical rod 1 through pivots 3. The tips of connecting rods 4, 4 of the same length are pivoted at equal distances from the middles of the rulers 2, 2 through pivots 5, 5. Further, the base ends are inserted in an overlapping state in a slide elongated hole 1a bored along the center of the vertical rod 1 and locked by set screws 6. An angle bent from a straight line is instantaneously divided into two parts using the rulers. Thus, the promptness and accuracy of formation of an angle required for civil engineering, building, wood working, interior, aluminium working and the other engineering can be expected and the free locking from can be manufactured at low cost.