What is the minimum number of sides a polygon can have?

A polygon is defined as a closed two-dimensional shape composed of a finite number of straight line segments connected end to end. The smallest configuration that fits the definition of a polygon is a triangle, which has three sides.

Polygons with fewer than three sides, such as a shape with two sides (which would essentially be a line segment) or a single, straight line (one side), do not meet the criteria of being a two-dimensional closed figure. Therefore, the minimum number of sides required for a shape to be considered a polygon is three.