yes
Polyhedrons are shapes with many faces
no because it has curved faces.
An octahedron, for example. 8 faces, 6 vertices.
6
check a reference book
A sphere has no faces an corners. The term "faces" and "corners" are applied to polyhedrons, figures with flat surfaces.
No because they have many faces which is the meaning of the word polyhedron
No, those bounded by only plane faces are but others are not.
True.
To study solid objects whose faces are all polygons.
Yes and the flat surfaces are called faces