Draw a triangle with sides of 2 cm, 3cm and 4cm and another one of 4cm, 6cm and 8 cm. Both will be SSS congruent.
SAS:
Draw a triangle with sides of 2 cm, 3 cm and another side of your choice. The angle between sides of 2 and 3 cm is 30 degrees. Now draw a triangle with sides of 4 cm, 6cm and another side of your choice (but this one cannot be the double of the 3rd side of the first triangle!) . The angle between the sides of 4 cm and 6 cm should be 60 degrees. Now you have 2 SAS congruent triangles.