The properties of triangles states that the third side is no less than the difference between the other 2 sides. So we can subtract B from A in number 1 to get 5. In number 2, we need to convert them both into twelfths in order to find the difference, 2/3 is 8/12 and 1 3/4 = 7/4. 7/4 in twelfths is 21/12. Now we subtract and ignore the denominators, 21 - 8 is 13. You now have 13/12 for number 2.
