Solution :
Steps of construction:
1. Draw ∆ABC with AB = 4 cm, BC = 5 cm and CA = 6 cm.
2. Draw a ray making an acute angle with BC on the side opposite to vertex A.
3. Mark three points B1, B2 and B3 on such that BB1 = B1B2 = B2B3.
4. Join B3C.
5. Draw a line parallel to B3C through B2 meeting at C'.
6. Draw a line parallel to BA through C' meeting at A'.
7. ∆A'BC' is the required triangle.