Which polygon has 8 sides?

An octagon is defined as a polygon with eight sides and eight angles. The term "octagon" is derived from the Greek words "okto," meaning eight, and "gonia," meaning angle. Therefore, when one refers to an octagon, it inherently implies that the shape has eight sides, conforming to its geometric definition.

In contrast, a quadrilateral has four sides, a pentagon consists of five sides, and a hexagon has six sides. Understanding the prefix associated with these shapes helps in identifying the number of sides: for example, "quad" refers to four, "pent" refers to five, and "hex" refers to six. Thus, when considering polygons, the knowledge of their numerical prefixes is key to determining their characteristics. Consequently, the octagon stands out as the correct answer within this context since it specifically refers to a polygon with eight sides.