Polyhedron.
A pyramid, as well as any other solid figure bounded by plane polygons or faces, is a polyhedron.
Any convex three dimensional figure with straight edges (or plain faces) will have polygons for bases so there is an infinity of such shapes.
Any polygons
In the context of polyhedra, they are polygons. Otherwise, they can be any shape you like.
a sphere
A pyramid, as well as any other solid figure bounded by plane polygons or faces, is a polyhedron.
Any convex three dimensional figure with straight edges (or plain faces) will have polygons for bases so there is an infinity of such shapes.
They are prisms. The bases may be any polygons with three or more sides.
Any polygons
In the context of polyhedra, they are polygons. Otherwise, they can be any shape you like.
Any regular polygon has two congruent faces. Many polygons have two or more congruent faces.
a polyhedron is any 3d figure with all flat polygons for sides(polygons have straight sides)
pyramid
Sphere
a sphere
Any figure with 8 faces is an octahedron. If it has 18 edges, it is a hexagonal prism.Any figure with 8 faces is an octahedron. If it has 18 edges, it is a hexagonal prism.Any figure with 8 faces is an octahedron. If it has 18 edges, it is a hexagonal prism.Any figure with 8 faces is an octahedron. If it has 18 edges, it is a hexagonal prism.
A polyhedron is a generic term to describe a closed 3-dimensional (solid) shape that is bounded by polygons. It can have 4 or more faces - any number.