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 1782 Henry Sidgier was issued a British patent for a rotating drum washer.   Nathaniel Briggs of New Hampshire received the first United States issued patent for a washing machine in 1797.There is very little known of this machine because a fire destroyed the records of it. Nathaniel Briggs of New Hampshire received the first United States issued patent for a washing machine in 1797. There is very little known of this machine because a fire destroyed the records of it.