Answer:
18ft
Step-by-step explanation:
If every cube is 1/4th foot in volume, then 4 cubes would be equivalent to 1ft. The box we need to measure is 4 cubes high, we can just count how many little cubes are on the top side and the amount of cubes would be at a 1 to 1 with how many square feet in volume the box is.
I'm not confident in this explanation but id be happy to answer questions in comments.
Hope i helped!
