a plane
A plane?
It is a plane that extends indefinitely in all directions. It is very easy to remember just think about what flys in the air and needs to land on a "flat surface that extends indefinitely in all directions" (the ground).
line
If the surface can be imagined, then it can be represented. Therefore, the answer to the question is that there is no such surface.
A plane =)
A plane
Plane
No, a ray extends infinately in one direction; but this can be any direction at all
A flat surface that extends forever is a plane
plane
A plane.
plane