The length of side AB can be calculated using the given ratio AC:AB = 8:5 and the value of AB, which is 54.

Step 1: Multiply the ratio with the given value of AB: 8 x 54 = 432 and 5 x 54 = 270.

Step 2: Now since the ratio of AC:AB is 8:5, we can say that the length of side AB is 270 units.

Step 3: If you want to find the length of side AC, you can simply multiply 8 x 8 = 64 and 64 is equivalent to AC, thus making its length equal to 64 units.

Overall, the length of side AB is 270 units and the length of side AC is 64 units.