The perimeter of a rhombus is equal to the sum of all four sides. If we let each side of the rhombus be represented by "s", then the perimeter would be 4s. In this case, the perimeter is given as 104 cm, so we can set up the equation 4s = 104. Solving for s, we find that each side of the rhombus is 26 cm.
The ratio of the diagonals of a rhombus is equal to the ratio of the lengths of the sides. In this case, the ratio is given as 5:12. Since we know that each side is 26 cm, we can set up the equation 5/12 = 26/x, where x represents the length of the shorter diagonal. Solving for x, we find that the shorter diagonal is 10 cm.
To find the longer diagonal, we can use the Pythagorean theorem. The diagonals of a rhombus form four right triangles, where the diagonals are the hypotenuses. The sides of these right triangles are half the lengths of the sides of the rhombus. Using the shorter diagonal as the hypotenuse and half the length of a side as one of the legs, we can set up the equation a^2 + b^2 = c^2, where a = 13 cm (half the length of a side) and c = 10 cm (the shorter diagonal). Solving for b, we find that the longer diagonal is 24 cm.
Therefore, the diagonals of the rhombus are 10 cm and 24 cm, which corresponds to answer choice б) 20, 48.