Definition:Hendecagon

Definition

A hendecagon is a polygon with exactly $11$ sides.

Regular Hendecagon

A regular hendecagon is a hendecagon which is both equilateral and equiangular.

That is, a regular polygon with $11$ sides.

That is, a hendecagon in which all the sides are the same length, and all the vertices have the same angle:

Also known as

A hendecagon can also be referred to as an undecagon.

Some sources give it as endecagon.

Also see

• Results about hendecagons can be found here.

Linguistic Note

The word hendecagon derives from the Greek hendeka, meaning eleven, and gon, deriving from the Greek for corner.

The word undecagon is a hybrid word whose first part derives from the Latin undecim, meaning eleven.

The word endecagon may be erroneous.

Sources

• 2008: David Nelson: The Penguin Dictionary of Mathematics (4th ed.) ... (previous) ... (next): undecagon
• 2014: Christopher Clapham and James Nicholson: The Concise Oxford Dictionary of Mathematics (5th ed.) ... (previous) ... (next): hendecagon
• 2014: Christopher Clapham and James Nicholson: The Concise Oxford Dictionary of Mathematics (5th ed.) ... (previous) ... (next): polygon
• 2021: Richard Earl and James Nicholson: The Concise Oxford Dictionary of Mathematics (6th ed.) ... (previous) ... (next): polygon