Respuesta :

All you are doing is multiplying the sides together:

7*5*2

=70

70 is the volume of the sandbox
We'll to find the volume of a Rectangular Prism, first you have to know this:
[tex]V=whl[/tex], so that means 
[tex]V=(7)*(5)*(2)[/tex], and [tex]7*5=35[/tex], so 
[tex]35*2=70[/tex]
Final Answer: [tex]V=70ft.[/tex]