A six faced 3d shape is called a cube.
Enneahedral
A hendecahedron.
A twelve sided shape is called a "dodecahedron" :D
A pyramid.
Decahedreon
It is a nonahedron.
An 8-faced 3D shape is called an octahedron. It is a polyhedron with eight triangular faces, 12 edges, and six vertices.
It is called a trihedron. It does not exist.
Dodecahedron.
A cube or a cuboid
Any six-sided shape is a hexagon.