Explanation:

- The area of the square is 576 cm².

- Therefore, the side of the square is v576 = 24 cm.

- The area of the rectangle is 1/3 of the square's area, i.e., 576 cm² / 3 = 192 cm².

- The breadth of the rectangle is given as 12 cm.

- Therefore, the length of the rectangle is 192 cm² / 12 cm = 16 cm.

- The perimeter of the rectangle is calculated as 2 × (length + breadth).

- So, the perimeter is 2 × (16 cm + 12 cm) = 2 × 28 cm = 56 cm.

- Option 3: 56 cm is the correct perimeter of the rectangle.