First we need to define what collinear and coplaner means.
It is said that 3 or more points are collinear if they all lie on the same line.
From the diagram, point R, S, T do not lie on the same line.
Hence point R, S and T are not collinear
For a point or line to be coplaner, it must line in the same plane
Also looking at the diagram, points R, S, T do not lie in the same plane.
Hence
