Many, an unspecified number. Poly, in Greek, means many. Polyhedra (singular polyhedron) means "many faced".
Decahedron
There are only 5 regular polyhedra: those with 4, 6, 8, 12 and 20 faces. If you know of 7 polyhedra there may be a Fields Medal (the Nobel prize for mathematicians) for you!
dodecahedron
dodecahedron
A twelve-faced shape is a dodecagon, also known as a dodecahedron.
A dodecahedron is a twelve-faced polyhedron.
Polyhedra are named by the number of faces they contain. The names are based on Classical Greek. Over time, some polyhedra have become known by common, non-Greek names, i.e. a regular hexahedron is commonly called a cube.
They are all polyhedra with 12 edges.
They are polyhedra, each with a square base.They are polyhedra, each with a square base.They are polyhedra, each with a square base.They are polyhedra, each with a square base.
NO, but prisms are polyhedra. Polyhedra include a lot more shapes than just prisms.
No. A pyramid is a polyhedron. Many pyramids are polyhedra.