Step 1 :Let's denote the length of the shorter leg as \(x\). Then, the longer leg is \(x+3\) and the hypotenuse is \(x+6\).
Step 2 :According to the Pythagorean theorem, we can set up the following equation: \((x+3)^2 + x^2 = (x+6)^2\).
Step 3 :Solving this equation, we get two solutions: -3 and 9. However, the length of a side of a triangle cannot be negative, so we discard -3.
Step 4 :Therefore, the length of the shorter leg is 9 cm.
Step 5 :Substituting \(x=9\) into \(x+3\) and \(x+6\), we find the lengths of the longer leg and the hypotenuse.
Step 6 :The length of the longer leg is 12 cm and the length of the hypotenuse is 15 cm.
Step 7 :Final Answer: The length of the shorter leg is \(\boxed{9 \mathrm{~cm}}\), the length of the longer leg is \(\boxed{12 \mathrm{~cm}}\), and the length of the hypotenuse is \(\boxed{15 \mathrm{~cm}}\).