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.
Know MoreA polygon refers to any two-dimensional shape that consists of only straight edges and has a closed shape. The most common polygons are those with a small amount of sides, such as triangles with three sides and squares with four sides. A dodecagon has 12 straight edges in a closed loop along with 12 vertices where the edges meet.
Learn more about ShapesA 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 polygon with three sides is called a triangle. All triangles consist of three lines that are not collinear and three angles. Polygons can have any number of sides, but they must be closed figures.
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 >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.
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