Which of the following possibilities will form a triangle side = 15 cm, side = 7 cm, side = 7 cm

It is not possible to form a triangle with sides of 15 cm, 7 cm, and 7 cm because the sum of the two shorter sides must be greater than the longest side in order for a triangle to be formed. In this case, 7 + 7 = 14, which is less than 15.