Which of the following shapes has 8 sides?

An octagon is defined as a polygon with exactly eight sides and eight angles. The term "octagon" comes from the Greek words "okto," meaning eight, and "gonia," meaning angle. This shape is commonly recognized in both geometry and everyday contexts, such as stop signs, which are shaped as regular octagons.

In contrast, a heptagon has seven sides, a nonagon has nine, and a decagon has ten. Each of these shapes is defined by the specific number of sides it possesses, which makes the octagon the correct answer for this question about a shape with eight sides.