zero
3
Three.
A plane can be determined by three points, as long as the three points do not lie along a single line.
To create a plane, infinitely many. To uniquely determine a plane, just three.
To create a plane, infinitely many. But to uniquely define one, 3 are enough.
There are infinitely many points in a plane.
Any Euclidean plane has infinitely many points.
many
It takes three points to make a plane. The points need to be non-co-linear. These three points define a distinct plane, but the plane can be made up of an infinite set of points.
A minimum of three points are required to define a plne (if they are not collinear). And in projective geometry you can have a plane with only 3 points. Boring, but true. In normal circumstances, a plane will have infinitely many points. Not only that, there are infinitely many in the tiniest portion of the plane.
Infinite.