Program: 78

Give three points (x1, y1), (x2, y2) and (x3, y3), write a c program to check if all the three points fall on one straight line.

Output:

 Enter the co-ordinates of first point (X1, Y1): -3 4
 Enter the co-ordinates of second point (X2, Y2): 3 2
 Enter the co-ordinates of third point (X3, Y3): 6 1
 ab: 6.324555     bc: 3.162278    ac: 9.486833
 ab + bc = ac
 All the three points fall on one straight line.