"Collinear" means "sharing" (or lying on) "the same line". "Non-collinear" means, well, not.Please, tell me what is the word "collinear points" and "non-collinear points" ?
Draw three points that aren't all in a line. See what you can draw.And with 3 non-collinear points as vertices, how many different triangles can i draw ?
Do a few drawings. See what conclusions you can come to....If given a choice of 4 points, no three of which are collinear, how many different triangles can i draw ?