3 dimensions of a cubic box and 2 dimensions is square area. Cubic measurements you are multiplying 3 dimensions. In this particular case the measurements are given, hence: 3×3×2.

The question gives height, width but not length. It gives depth units as 2 and also height 3 which is confusing because height and depth are usually the same. In this instance we shall assume the 2 units are the length.

To calculate the volume of a cuboid or prism you have to calculate the base area multiply by height.

Volume = base area (length × width) × height.

Base area = 3 × 3 = 9 units

Height 2 units

So now,

(Base area) 9 × (height) 2 = 18 units.

Hence since it is a prism. Also can be calculated;

Volume(prism) = Ar(base)×h

Volume(cuboid) = (lb)h = 3×2×3 = 18 unit²