I have one circle and one curved side. My curved side surface meets at a sharp point. I have no edges. What am I?

I have two congruent circles that are joined by a curved surface. I have no edges or vertices. I can roll. What am I?

I am round with no vertices and edges. What I am?

I have 6 same shaped faces, 12 equal edges, and 8 vertices. What am I?

I have 12 edges, 8 vertices, and 6 faces. I have both square and rectangular faces. What am I?