A pentagon is the name for a fivesided shape. A pentagon is a closed figure with five straight sides. Pentagons can be either convex or concave. While a convex pentagon has interior angles that are not greater than 180 degrees, a concave pentagon can have an interior angle that is greater than 180 degrees.
Likewise, pentagons also can be either regular or irregular figures. A regular pentagon is a figure or polygon in which all interior angles are equal and all five sides are also equal in length. In a regular pentagon, each interior angle equals 108 degrees and the exterior angles equal 72 degrees.The sum of the interior angles is 540 degrees or five multiplied by 108 degrees.
I believe it is a polygram. it is a pentagon.
http://wiki.answers.com/Q/What_shape_is_a_five_sid...

A pentagon is a geometric shape with five
http://www.chacha.com/question/whatisafiveside...

A 11 sided shape is called a hendecagon.
http://wiki.answers.com/Q/What_is_a_11_sided_shape...

giga=billion so i came up with gigagon by wacomoly
http://wiki.answers.com/Q/What+is+a+1+billion+side...
