Answer:
The amount of material to fill the box is: 0.3

Explanation:
Recall that the volume (V) of a box is the product of the area of its base (B) times its height (H): V = B * H
Therefore, since in this case the area of the base is:

and the box's height is:

The total volume of the box (and what you need of material to fill it) is:
