You really have to declare to what degree you are asking. You could take a very carefully grown crystal and define a plane based on its lattice structure. But the atoms are not all perfectly placed on the lattice once you zoom in far enough. There’s even gaps between the atoms! A “plane” of carbon looks more like a net to an observer on the scale of those atoms.

Is an electron a perfect sphere? Scientists probably thought so in 1900 but now ask a physicist and they will say “No, probably not”.

And yes, as others have stated, our space time is not perfectly Euclidean so that’s another level of uncertainty. How do you measure the small imperfections in a Euclidean model when actual space time isn’t Euclidean?

As a professor used to tell my class, there are no 0s.