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!
Bipyramids are a class of polyhedra with more faces than vertices.
Regular polyhedra have identical faces.
dodecahedron
dodecahedron
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!
They are called "faces".
Bipyramids are a class of polyhedra with more faces than vertices.
Regular polyhedra have identical faces.
There are a few families of polyhedra with identical faces. There are none whose faces have 6 or more sides. There is no special name for polyhedra whose faces are pentagons or pentagrams. A dodecahedron is an example. If coplanar faces are disallowed, the only polyhedron with quadrilateral faces are the cube and rhombohedron. There are infinitely many polyhedra with equilateral triangular faces: the tetrahedron, octahedron and icosahedron are examples.
Strictly speaking, no. But, as the number of faces increases, polyhedra can approximate cylinders or spheres and so can "roll".
Polyhedra (singular = polyhedron).
dodecahedron
dodecahedron
A tetrahedron or triangular pyramid.
The Euler characteristic for simply connected polyhedra isF + V = E + 2 where F = # faces, V = # vertices and E = # edges.
The Euler characteristic for polyhedra then requires that thye shape has no vertices! And that means it cannot be a polyhedron. I suggest you count the faces and edges again.