With a fixed surface area you can actually maximize the volume of the box without using multi-variable calculus. Here's how:
Suppose the dimensions are x, y, z with 2(xy + yz + zx) = C for some constant C. This implies xy + yz + zx = C1 for a different constant C1. We will use what mathematicians call the AM-GM inequality (Arithmetic mean - geometric mean inequality) which says that, for some positive numbers, the arithmetic mean is always greater than or equal to the geometric mean, with equality occurring iff all the numbers are equal.
The AM-GM inequality says that
(xy + yz + zx)/3 >= (xy*yz*zx)1/3 (couldn't do cube root)
((xy + yz + zx)/3)3/2 >= xyz
The left side is equal to a constant (since it has the expression for surface area), so the maximal value of xyz (the volume) is equal to that constant. This happens when x = y = z, i.e. the box is cube-shaped.
They are characteristics of geometric shapes. However, there is no simple relationship. A rectangle with a given perimeter can have a whole range of areas.
make it spherical
Given a sphere of radius r, Surface area = 4{pi}r2 Volume = (4/3){pi}r3
The maximum area with straight sides and a given perimeter is a square.The sides of the square are (68/4) = 17 inches.The area is (17 x 17) = 289 square inches
By dividing its cross-section area into its volume
The maximum area for a rectangle of fixed perimeter is that of the square that can be formed with the given perimeter. 136/4 = 34, so that the side of such a square will be 34 and its area 342 = 1156.
They are characteristics of geometric shapes. However, there is no simple relationship. A rectangle with a given perimeter can have a whole range of areas.
increase surface area for a given volume
make it spherical
Given a sphere of radius r, Surface area = 4{pi}r2 Volume = (4/3){pi}r3
By dividing its cross-section area into its volume
The maximum area with straight sides and a given perimeter is a square.The sides of the square are (68/4) = 17 inches.The area is (17 x 17) = 289 square inches
Given the surface area, where S=surface area, the formula for finding the volume isV = √(S / 4pi)
The spherical shape is the smallest surface area for a given volume. This comes about naturally when a surface under pure surface tension contains a fluid volume.
That's volume. Area is the measurement of a given surface.
In general the larger the perimeter (of a flat shape) the greater the area. Given two congruent shapes the one with the larger perimeter has a greater area.But two shapes that are not congruent (or almost so) do not follow this rule: for example a rectangle fifteen units long and one unit wide has an area of 15 square units and a perimeter of 32 units. While a square with edges four units has an area of sixteen square units (one more than the other rectangle) but a perimeter of only sixteen units (half that of the long thin rectangle).So too with surface area and volume. Of two congruent 3 dimensional shapes, the one with the larger volume will also have a larger surface area.
A sphere