Ohio Assessments for Educators (OAE) Mathematics 2025 – 400 Free Practice Questions to Pass the Exam

An octagon is defined as a polygon with eight sides and eight angles. The term "octagon" comes from the Greek words "okto," meaning eight, and "gonia," meaning angle. This shape has a total of 8 sides and often is depicted in various forms, such as the standard stop sign which is a regular octagon where all sides and angles are equal.

In contrast, other shapes listed have a different number of sides: a heptagon has seven sides, a nonagon has nine sides, and a decagon has ten sides. Thus, when seeking a shape with exactly eight sides, the correct answer is clearly the octagon.