An open door creates an angle. How cool is that? The protractor—used to measure angles and make detailed drawings—is over 500 years old. Yet it's still an essential tool for engineers, architects, math teachers, drafters, and surveyors. Personalized doormat is available in two styles: A (for doors that open inward) and B (for doors that open out). Simply position the extra-wide mat so the center is at the door hinges, and the door will do the rest. Mat is woven polyester with a skid-resistant neoprene backing. 66" x 46". Best use: an office or classroom indoors. Mat may also be used outdoors in a sheltered area away from direct sunlight.