Answer:72 cm^2
Explanation:
Take the area of each face: smallest rectangles have areas of 6 cm^2 each, longer rectangles have area of 12cm^2 each, and largest rectangles have area of 18 cm^2 each. Add these up and multiply by two, since there are two of each face in this format: 2 * (6 + 12 + 18) = 72 cm^2