How about a cylinder or a cuboid
5
It is a prism with non-polygonal bases. The bases simply be two identically shaped "blobby" shapes.
a square
No but a cylinder does have 2 parallel bases
Yes, every prism has 2 parallel bases.
2
There are several cases: any 3 dimensional or more object. Since a polygon is defined as being confined to a single plane, any shape that violates the plane is not a polygon but may still have parallel bases. For cases in only 2 dimensions: Any object that has curves in addition to the parallel bases. A polygon's definition includes only straight sides. Finally, unclosed shapes can have 2 parallel bases with out being polygons even if in a single plane and made up of only straight line sides. A polygon must be closed.
A cylinder and a rectangular prism both have two parallel and congruent bases. However, the bases of a cylinder are circles, while the bases of a rectangular prism are rectangles. Both shapes have flat surfaces and straight edges.
yes
A prism and a cube.
No
Yes