Which figure is formed by three non-collinear points?

There is one and only circle passing through three non-collinear points.

How many lines can be drawn passing through three non-collinear points

Observe the figure and name Collinear points

How many lines can be drawn passing through three collinear points ?

Find the number of triangles formed by joining 12 points if a) no three points are collinear b) four points are collinear.

Which of the following set of points are non-collinear?

There are n points in a plane. Find the number of straight lines that can be obtained by joining points if a) no three points are collinear. b) p points are collinear.