Given three distinct points in a plane, how many lines can be drawn by joining them ?
Through three given points, one line can be drawn of they are collinear and three of they are non-collinear.
Out of 18 points in a plane, no three are in the same straight line except 5 points which are collinear. How many straight lines can be formed by joining them?
There are 20 non-collinear points in a plane. How many (a) straight lines (b) triangles can be drawn by joining these points?