en.wikipedia.org/wiki/Hendecagon

In geometry, a hendecagon (also undecagon or endecagon) or 11-gon is an eleven-sided ... The area of a regular hendecagon with side length a is given by. A = 11 4 a 2 ... The regular hendecagon has Dih11 symmetry, order 22. Since 11 is a ...

en.wikipedia.org/wiki/List_of_polygons

A regular pentagon has 5 equal edges and 5 equal angles. In geometry, a polygon /ˈpɒlɪɡɒn/ is traditionally a plane figure that is bounded by a finite chain of straight line segments closing in a loop to form a closed chain or circuit. These segments are called its edges or sides, and the points where two ... eleven , eleventh, hendeka, hendekatos.

www.math.com/tables/geometry/polygons.htm

What is a Polygon? A closed plane figure made up of several line segments that are joined together. The sides do not cross each other. Exactly two sides meet ...

www.mathsisfun.com/shape.html

2D Shapes. Regular Polygons. A polygon is a plane (2D) shape with straight sides. To be a regular polygon all the sides and angles must be the same: ...

en.wikibooks.org/wiki/Geometry_for_Elementary_School/Plane_shapes

A shape with only straight sides as edges is called a polygon(POL-ee-gone). Polygons must .... Hendecagons (also known as undecagons) have eleven sides.

answers.yahoo.com/question/index?qid=20061121092221AANGCFa

Best Answer: Polygon names Name Sides : henagon (or monogon) 1 digon 2 triangle (or trigon) 3 quadrilateral (or tetragon) 4 pentagon 5

faculty.kutztown.edu/schaeffe/Tutorials/General/Polygons.html

For polygons with 3 through 20 sides, simply add "gon" to the prefixes at the left ( although a trigon is more commonly called a triangle and a tetragon, ...

www.infoplease.com/science-health/numbers-and-formulas/polygons-how-many-sides

A geometrical figure with three or more sides is called a polygon or a polyhedron. Here are the ... For example, a triangle has 3 sides and 3 angles. A pentagon ...

www.reference.com/math/11-sided-shape-called-2f7f8996d4b356d2

A: Any shape that has four sides at right angles to each other with diagonals of equal length is a rectangle. The two special types of rectangles are squares .