Check is a point (x,y) is between two points drawn on a straight line

Question

I have drawn a line between two points A(x,y)---B(x,y) Now I have a third point C(x,y). I want to know that if C lies on the line which is drawn between A and B. I want to

Answer 1

An easy way to do that I believe would be the check the angle formed by the 3 points. If the angle ACB is 180 degrees (or close to it,depending on how accurate you want to be) then the point C is between A and B.