Answer:
9 cm
Step-by-step explanation:
The volume of a rectangular prism can be calculated as
[tex]V=\text{length}\cdot \text{width}\cdot \text{height}.[/tex]
Since the width is 2 cm and the height is 4 cm, then
[tex]72=2\cdot 4\cdot \text{length},\\ \\\text{length}=\dfrac{72}{8}=9\ cm.[/tex]
