It is called a cone.
A right cylindrical cone has a circle for a base and one vertex. a diagram is shown on unitmath.com
cone
L shape
cone
A cone.
c
A cone
it is a 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).
It is called a cone.
a cone
How about a sphere as an example that fits the given description
A right cylindrical cone has a circle for a base and one vertex. a diagram is shown on unitmath.com
cone
L shape
A cone.