An 11-sided polygon is called a hendecagon. In order for an 11-sided shape to be considered a hendecagon, its sides must all be straight and form a closed shape.
A five-sided polygon is called a pentagon. A pentagon also has five vertices and five interior angles, which add up to a total of 540 degrees.
A 10-sided polygon is referred to as a decagon. "Deca" is used as a prefix that means 10, and it is used to create compound words.
A polygon is a plane figure that has "at least three straight sides and angles," according to Oxford Dictionaries. However, polygons can have more than three sides; most have five or more.
A polygon with 10 sides is called a decagon. The word comes from the Greek words for "ten" ("deka") and for "angle" or "corner" ("gonia"). Decagons have 10 angles and 10 sides.
A polygon with seven sides is called a heptagon. A polygon is a closed geometric shape that has at least three sides and angles.
A 100-sided polygon is called a hectogon, centagon or 100-gon. In general, any n-sided polygon with over 12 sides is called an n-gon. While there are other conventions for naming polygons with any number of sides, it is most common to use the n-gon form.
An 8-sided polygon is called an octagon. One common use of the octagon is in the iconic red stop sign that's used throughout the United States.
A polygon with 25 sides is called a icosikaipentagon. Polygon names are constructed according to the tens unit and the single digit unit.
An 11-sided polygon is called a hendecagon. It is also known as the undecagon or unidecagon. However, the term "hendecagon" takes precedence over these variants because of its consistency in using a Greek prefix and suffix, instead of combining a Roman prefix with a Greek suffix.