Simplify the product into the form a/b for integers a and b that are relatively prime.
If x and y are the lengths of two sides of a triangle such that the product xy = 18, where x and y are integers, then how many such triangles are possible?
If a, b, c and d are distinct pairwise co-prime positive integers such that a^2 + b^2 = c^2 + d^2, find the lowest possible value of a + b + c + d?
