The sharp angles of the slender triangle ruler are 30 ° and 60 ° respectively. Two identical slender triangular rulers can form an equilateral triangle. The length of the beveled edge of the slender triangle ruler is twice the length of the short square edge.

The multi-function triangle ruler is a circle drawing mechanism composed of a rotating ring and a rotary table at the two sharp corners of the original triangle ruler, a needle-shaped angle drawing mechanism at the protractor, a frame at the bottom edge, and a slot rail in the frame. The slot rail is equipped with a positioning mechanism composed of a distance plate, elastic material, slide plate and a parallel line drawing mechanism composed of a slide block embedded in the slot for sliding.