Britannica Sources used in this answer

How many faces does an octahedron have?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

Map of the Greco-Roman world highlighting the birthplaces of notable ancient mathematicians, marked with the pi symbol and labeled with their names. Cities such as Athens, Alexandria, Syracuse, and Miletus are shown around the Mediterranean, with modern country boundaries outlined. An inset provides detail for the region of Greece and western Anatolia. — geometry This map spans a millennium of prominent Greco-Roman mathematicians, from Thales of Miletus (c. 600 bce) to Hypatia of Alexandria (c. 400 ce).

An octahedron is a polyhedron that has eight faces.12

In the context of Euclidean geometry, the octahedron is one of the five Platonic solids, which are regular polyhedra characterized by congruent faces and angles. Specifically, an octahedron is composed of eight congruent equilateral triangular faces.32