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.
Know MoreAnother less common name for the nonagon is "enneagon." The name is derived from the Greek word "enneagonon," where "ennea" means "nine," and "gonon" means "corner." Thus, "enneagonon" means "nine corners," which is an accurate description of this polygon. Nonagons can be divided into regular and irregular nonagons. A regular nonagon has nine equal sides and nine equal internal angles of 140 degrees. An irregular nonagon has at least one side either longer or shorter than the rest.
Learn more about ShapesA two-dimensional shape with nine straight sides is called a nonagon. This nine-sided polygon, which also has nine edges or vertices, is also called an enneagon. The term enneagon is preferable, but less popular than the name nonagon because the latter is simpler to spell and pronounce.
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.
Full Answer >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.
Full Answer >