cone
a sphere
A cone. A hemisphere.
A cone.
A sphere has one surface that's also curved and has no base.
The solid shape you are describing is called a cone. A cone has a circular base and narrows to a single vertex, or apex, at the top. Its curved surface connects the base to the vertex, distinguishing it from other solid shapes.
a sphere
A paraboloid.
a cone.
A line?
A sphere that has been sliced by a plane will have a circular base and a curved surface. In the special case that this plane goes through the centre of the sphere, the shape will be a hemisphere. in simple terms it would actually be a cone...
It has just the one curved surface area and and its base
A cone.