In geometry, a polygon is traditionally a plane figure that is bounded by a finite chain of strait line segments closing in a loop to create a closed chain or circuit. These line segments are called edges or sides, and the points where two of these edges meet are the polygon’s vertices or corners. The inside of the polygon is occasionally called its body. An n-gon is a polygon with n sides. A polygon is a 2-dimensional instance of the more general polytope in any number of dimensions.

The word polygon comes from the Greek polus, meaning “much“, and gonia, meaning “corner”, “angle“, or gonu, meaning “knee”.

The basic geometrical notion has been adapted in a variety of ways to match particular purposes. Mathematicians are frequently concerned only with the bounding closed polygonal chain and with simple polygons which don’t self-intersect, and they often define a polygon consequently. A polygonal boundary might be permitted to intersect itself, creating star polygons. Geometrically two edges or sides meeting at a corner are required to create an angle that isn’t straight; otherwise, the line segments might be thought to be parts of a single edge; however mathematically, such corners or vertices might occasionally be permitted.

Image Caption: An assortment of polygons. Credit: CountingPine/Wikipedia