Answer:
Cubic inches
Step-by-step explanation:
If you are dealing with area on a 2D shape, you use normal units (cm, m, in, ft, etc.)
If you are dealing with 3Ds, you use square or cubic.
In this case, you are to calculate for the volume.
To calculate volume, you have to multiply the height, width, length.
Let's say they all measure the same.
So,
a × a × a = a³
a represents the unit of measurement.
Therefore, the volume must have a cubic unit.