Answer:
[tex]h=12ft[/tex]
Step-by-step explanation:
The formula one would use for finding the volume of a rectangular prism is as follows:
With this in mind, let's plug in the given variables in the question for this formula.
[tex]V=648ft^3[/tex]
[tex]l=6ft[/tex]
[tex]w=9ft[/tex]
[tex]h=[/tex] ?
[tex]V=lwh\\648ft^3=(6ft)(9ft)h[/tex]
[tex]648ft^3=(6ft)(9ft)h\\648ft^3=(54ft^2)h\\\frac{648ft^3}{54ft^2}=\frac{(54ft^2)h}{54ft^2}[/tex]
[tex]\frac{648ft^3}{54ft^2}=\frac{(54ft^2)h}{54ft^2}\\12ft=h[/tex]
If involving units only confuses you, like it does for me, you can remove them like so, you just need to know what units your solution uses instead of being able to come to the proper units by using math.
[tex]V=lwh\\648=(6)(9)h\\648=54h\\\frac{648}{54}=\frac{54h}{54}\\12ft=h[/tex]