Which solid has 8 faces and is often referred to as a double pyramid?

An octahedron is indeed a solid that has 8 faces, and it is commonly referred to as a double pyramid due to its geometric structure. It consists of two pyramids joined at their bases. Each face of an octahedron is a triangle, and there are 8 such triangular faces in total, which contribute to its unique shape.

In an octahedron, the arrangement and connectivity of the faces create a symmetrical shape, making it a member of the family of polyhedra. The vertices and edges of the octahedron also exhibit high degrees of symmetry, further reinforcing its classification. This specific characteristic of having 8 triangular faces, along with its appearance resembling two pyramids base-to-base, is what makes it distinctive compared to other solids like a cube, a single pyramid, or a prism.