it if called a edge for a 3D shape
A cone has either one or two surfaces and either one or no edges.
A cone.
A Cylinder
A cone.
it if called a edge for a 3D shape
A cone has either one or two surfaces and either one or no edges.
A cone.
A Cylinder
A shape with one vertex, one edge, and two faces is called a cone. The vertex is the point where the edges meet, the edge is the line where the faces meet, and the faces are the flat surfaces of the shape. In the case of a cone, one face is the circular base and the other face is the curved surface.
A cone.
One curved surface (two if it is hollow) and no edges.
The edge formed by two surfaces meeting each other is called a "corner" or a "boundary."
Cone
The edge of a shape can be considered a point where two sides meet to either form an angle (inside) or edge (outside).
A cone would fit the given description
They form a line or edge.