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 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.
Full Answer >A nine-sided polygon is called a nonagon. The prefix "non" is derived from the Latin "nonus," which means "ninth" to allude to the nine sides and angles of the polygon.
Full Answer >A 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 12-sided two-dimensional polygon is called a dodecagon. A regular dodecagon has 12 sides that are all the exact same length and internal angles that are 150 degrees each. Since there are 12 internal angles, the total internal angles add up to 1,800 degrees.
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