Answer:
486 ft²
Step-by-step explanation:
If the cube volume is 729 ft³, then the length of one side is
∛(729 ft³) = 9 ft.
The cube (like all cubes) has 6 identical sides, each 9 ft by 9 ft, or 81 ft².
Label each side with '81 ft²'
Since there are 6 such sides, the total surface area is 6(81 ft²) = 486 ft²
