It is something that is not a polyhedron. that would include
A non polyhedron with 0 bases is a sphere.
Examples of non polyhedron are cone cylinder spere
A polyhedron is a three-dimensional solid with flat faces, straight edges, and sharp corners, while a non-polyhedron does not have these characteristics. Polyhedra are made up of polygons that enclose a single region of space, while non-polyhedra may have curved faces or intersecting edges. In mathematical terms, a polyhedron satisfies Euler's formula (V - E + F = 2), where V is the number of vertices, E is the number of edges, and F is the number of faces, while a non-polyhedron does not.
A non polyhedron does not have these properties, maybe it is not closed, maybe one or more of the sides is a curved surface. In some branches of topology the sides of a polyhedron cannot intersect each other.http://wiki.answers.com/What_is_the_difference_between_a_polyhedron_and_a_non_polyhedron#ixzz185DDOyd9
Assuming that you mean diagonal (not diagnol) lines, they are straight lines that join non-adjacent vertices in a polygon or polyhedron.
A polyhedron has "many sides" (by definiton). The only 3-D shape which does not have "many sides" is a sphere (which technically only have one "side").
A cylinder is one example.
If you mean a decahedron then it is a polyhedron with 10 faces
A shape with a lot of sides and angles.
No, they are the faces of the polyhedron.
If, by "sides" you mean faces, then the answer is a pentahedron.
The definition of polyhedron. If it was not faceted it would not be a polyhedron.