A company is constructing an open-top, square-based, rectangular metal tank that will have a volume of 66 ft^3

Question

. What dimensions yield the minimum surface area? Round to the nearest tenth, if necessary.

Answer 1

The minimum surface area will be a cube. (It would be a sphere, but your def says it has a square base.)

So x^3 = 66 cu.ft.
x = 4.04 ft

Surface area, BTW, would be 5 * x^2, since there is no top, or 81 sq. ft. of material.