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.

The transformer has a primary coil with 480 turns and decreases the voltage from U1 = 880V to U = 220V. To determine the transformation ratio and the number of turns in the secondary coil when the transformer is unloaded, we can use the formula:

K = N2/N1 = U1/U2 = N1/(N1+N2)

Substituting the values given in the problem:

K = 480/(480+N2) = 880/220 = 4

Solving for N2, we get:

N2 = 480

Therefore, the transformation ratio is 4 and the number of turns in the secondary coil is 480 when the transformer is unloaded.