What geometrical shape forms the hole that fits an Allen Wrench?
Answer: An Allen Wrench is an L-shaped metal bar used to drive bolts and screws that have a hexagonal socket in the head. In 1909, William G. Allen patented a method of cold-forming screw heads around a hexagonal die. Published advertisements for the “Allen safety set screw” by the Allen Manufacturing Company of Hartford, Connecticut, exist from 1910. Although it is unlikely that Allen was the first person to think of a hex socket drive, his patent for a manufacturing method and his realized product appear to be the first.
In geometry, a hexagon (from Greek ἕξ hex, “six” and γωνία, gonía, “corner, angle”) is a six sided polygon or 6-gon. The total of the internal angles of any hexagon is 720°.