square base pyramid
Spherical
Cone
A cone perhaps?
Sphere, torus, moebius strip
In order to be 3D it must have a length, a width, and a height. EDIT: Mobius Strip
Its an Cylinder
Spherical
Sphere
A cone?
A cone.
Cone
hemisphere
The shape you are describing is a cylinder. A cylinder has two circular faces, which are also known as bases, and one rectangular face, which is called the lateral face. The lateral face of a cylinder is formed by unrolling the curved surface of the cylinder into a flat shape, creating a rectangle.
A cone perhaps?
a cone
cone
cylinder