Answer:
Postulate: A plane contains at least three points not all on one line.
Step-by-step explanation:
Given:
G and H are different points in a plane R.
Then a third Point exists in R not on GH.
Suppose there are three points G, H and K. These are non linear points which means they do not lie on the same line. Having three points on the plane means that the plane cannot be drawn with just two points.
These points would make a triangle which is plane R. This is because if the plane could be drawn with two points then that would form a line. But here we know that plane should have at least three points.