stable, crystal-clear plastic. tracing all of the edges. scale of 1 mm. Big: 45′′, hypotenuse 36′′, 30′′/60′′, hypotenuse 41′′. 45°, hypotenuse 32 cm; 30°/60°, hypotenuse 37 cm; medium. Tiny: 45′′, hypotenuse 25′′, 30′′/60′′, hypotenuse 29′′ each.