The flat surface that goes on and on in all directions has no boundaries. This flat surface is called infinite surface. Accordingly, the answer is that the flat surface that goes on and on in all directions is called an infinite surface.
Such a shape probably does not have a specific name.
Each flat surface is a face
If you mean 1 flat surface and 1 vertex, then the only thing I can think of is a cone.
It is a face.
what is the name of an flat surthis
A base
A face.
A face.
A floor.
Base.
Map
A flat mirror is generally referred to simply as a flat mirror. It is a mirror with a flat reflective surface that does not have any curvature.
It is a plane.
A face is a flat surface. The only solid with no flat surfaces is a sphere.
It does not have a flat surface.
The name given to flat areas between bumps and hollows on Earth's surface is "plateau". Plateaus are elevated flat-topped areas that are higher than the surrounding terrain.