A right cylindrical cone has a circle for a base and one vertex.
a diagram is shown on unitmath.com
cone
circle
It is a cone
cone
A cone.
A cone. The base is circular and curved, and the tip of the cone is the vertex.
A cone.
i ant gpt a skooby
Cone
An infinite cone.
One possible answer is an infinite cone. Spheres have one face but no vertex. No physical 3-D shape can have a vertex without having more than one face (a real cone typically has two: side and bottom).
a cone