A polyhedron (plural polyhedra or polyhedrons) is often defined as a geometric object with flat faces and straight edges (the word polyhedron comes from the Classical Greek ÏÎ¿Î»ÏÎµÎ´ÏÎ¿Î½, from poly- , stem of ÏÎ¿Î»ÏÏ, many, + -edron, form of ÎµÎ´ÏÎ¿Î½, base, seat, or face). polyhedron is any three-dimensional figure with flat surfaces that are polygons. Specifically, any geometric shape existing in three-dimensions and having flat faces, each existing in two-dimensions, which intersect at straight, linear edges.
In 1839, Charles Goodyear invented rubber vulcanization, but the first rubber condom was not produced until 1855. Just a few short years later, the majority of rubber companies were producing condoms as well. These condoms were reusable, which meant they were much more affordable.
In 1912, a German named Julius Fromm developed a new, improved manufacturing technique for condoms: dipping glass molds into a raw rubber solution. Called cement dipping, this method required adding gasoline or benzene to the rubber to make it liquid. Latex, rubber suspended in water, was invented in 1920. Latex condoms required less labor to produce than cement-dipped rubber condoms, which had to be smoothed by rubbing and trimming.