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.
Know MoreThe name for a hendecagon is derived from "hendeka," which is the Greek word for 11. Like other polygons, hendecagons can be either regular or irregular. A regular hendecagon consists of 11 sides equal in length and internal angles of approximately 147.273 degrees. An irregular hendecagon is any 11-sided polygon where one or more of the sides are different lengths from the others. An example of a real life hendacagon is the Canadian loonie.
Learn more about ShapesA nine-sided polygon is called a nonagon. Another name for a nine-sided polygon is enneagon. The general accepted names are "n-gon" where n is the number of the sides of the polygon.
Full Answer >A six-sided polygon is called a hexagon. A polygon is an enclosed figure with straight lines that do not cross over one another. Polygons do not necessarily have equal sides. A convex polygon has all angles pointing outward, but in a concave polygon, some angles can point inward.
Full Answer >A polygon with seven sides is called a heptagon. A polygon is a closed geometric shape that has at least three sides and angles.
Full Answer >A 20-sided polygon is called an icosagon. Along with having 20 sides, all icosagons have 20 interior angles that add up to a total of 3240 degrees.
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