Polygons - Classification, Angles
Polygons are closed plane figures bounded by three or more line segments. In the world of geometry, polygons abound. The term refers to a multisided geometric form in the plane. The number of angles in a polygon always equals the number of sides.
Polygons are named to indicate the number of their sides or number of noncollinear points present in the polygon.
A square is a special type of polygon, as are triangles, parallelograms, and octagons. The prefix of the term, poly comes from the Greek word for many, and the root word Gon comes from the Greek word for angle.