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.
Related Terms. A form of plastic invented in the 1930s by the Molex company. The material was developed by the late Frederick August Krehbiel. In 1938, he founded the Molex Products Company in Brookfield, Ill. to manufacture a variety of products from this material, including clock cases, flower pots, valve wheels and salt tablet dispensers. In the 1950s, Molex rapidly penetrated the appliance market with its low-cost connector terminal blocks.