Answer :
The difference is 3ft since the surface area for the prism is 57, and the surface area for the cube is 54.
You can use the surface area formula
2(wl+hl+hw) = Area
2·(3·4.5+2·4.5+2·3)=57
And a cubes surface area formula
6a^2 = Area
6·32=54
You can use the surface area formula
2(wl+hl+hw) = Area
2·(3·4.5+2·4.5+2·3)=57
And a cubes surface area formula
6a^2 = Area
6·32=54