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.
The 1800s saw a whole slew of innovations: sugar-coating and gelatin-coating of pills--as well as the invention of gelatin capsules. It also rang the death knell for the old, original pill with the invention of the compressed tablet. In 1843, a Brit named William Brockedon invented a totally different kind of pill. You'd put powder in a tube and then compress it to solidity with a mallet. Eventually, his invention caught on.