If six line segments having lengths 2, 3, 4, 5, 6, 7 units, Find the number of different line segments which cannot form a triangles.
To form a triangle sum of two sides of triangle should be greater than third side. But
2+ 3 is NOT greater than 5, 6 and 7units
2 + 4 is NOT greater than 6 and 7units
2 + 5 is NOT greater than 7units
4 + 3 is NOT greater than 7units
So, total number of different line segment which cannot form triangles = 7