Alvin adjustable trigonometry triangles, computing trig triangles include graduations of rise, slope and degrees. The adjustable right triangle is great fir classroom or real world applications for calculating length and distance using trig functions plus more. The trig triangle has inking edges on all three sides, and the graduations of rise, slope, and degrees are hot-stamped on the triangle. Thumb screws are is used to adjust the angle and lock it securely at desired rise, slope, or angle. The triangles are made of 0.12" thick, light blue, optically clear acrylic. And come with detailed instructions.