Hendecagon of a regular hendecagon is still impossible even with the usage of an angle trisector. It can, however, be constructed via neusis construction and also via two-fold origami. Close approximations to the regular hendecagon can be constructed, however. For instance, the ancient Greek mathematicians approximated the side length of a hendecagon inscribed in a unit circle as being 14/25 units long. The following construction description is given by T. Drummond from 1800: On a unit circle: The "regular hendecagon" has Dih symmetry, order 22. Since 11 is a prime number there is one subgroup with dihedral symmetry: Dih, and 2
How many angels can dance on the head of a pin? How many angels can dance on the head of a pin? The question "How many angels can dance on the head of a pin?" (alternatively ""How many angels can stand on the "point" of a pin?"") is a reductio ad absurdum of medieval scholasticism in general, and its angelology in particular, as represented by figures such as Duns Scotus and Thomas Aquinas. It is first recorded in the 17th century, in the context of Protestant apologetics. The question has also been linked to the fall of Constantinople, with the imagery of scholars debating about minutiae while the Turks besieged the