An 11 sided polygon is called a hendecagon, or sometimes an undecagon.
The term ‘hendecagon’ is derived from the Greek words ‘hendeka,’ meaning eleven, and ‘gonia,’ meaning angle. In geometry, polygons are named based on the number of sides they have. For example, a triangle has three sides, a quadrilateral has four, and so on. Therefore, an 11 sided shape specifically gets its name from having eleven angles and sides.
While hendecagons are not commonly encountered in everyday life, they can be useful in various mathematical contexts, including discussions about polygon properties and calculations related to them.