Regular Hendecagon

The regular hendecagon is the regular polygon with 11 sides, as illustrated above, and has Schläfli symbol .

The regular hendecagon cannot be constructed using the classical Greek rules of geometric construction.

The rim of the U.S. Susan B. Anthony dollar coin was a regular hendecagon, as illustrated above.

The inradius, circumradius, and area of the regular hendecagon with unit side lengths are

			(1)
			(2)
			(3)

These can be written exactly as the polynomial roots

			(4)
			(5)
			(6)