What is a polygon?

A polygon is defined as a two-dimensional figure that is composed entirely of straight line segments connected to form a closed shape. Each line segment in a polygon is referred to as a side, and the points where two sides meet are known as vertices.

The essence of polygons lies in their being flat (two-dimensional) and having a finite number of sides (line segments) that enclose a space. Polygons come in various forms, such as triangles, quadrilaterals, pentagons, and so on, depending on the number of sides they have.

In contrast, a three-dimensional figure would represent a shape that has depth in addition to width and height, which is not suitable for the definition of a polygon. A single line segment cannot qualify as a polygon since polygons require at least three sides to enclose a space. Lastly, a shape with no sides does not fit the criteria for a polygon, as the very definition hinges on the presence of straight sides that create the polygonal form.