An eight-sided shape is called an octagon. The term "octagon" comes from the Greek words "okto," meaning eight, and "gonia," meaning angle. Each of the eight sides meets at a vertex, creating eight angles. Regular octagons have equal sides and angles, while irregular octagons can have sides and angles of different lengths. Octagons are commonly seen in everyday life, such as in stop signs on the road. They can also be found in architecture and design, where their unique shape adds visual interest. The internal angles of a regular octagon measure 135 degrees each, totaling 1080 degrees for all angles combined.