What is the formula for surface area of a box?

1 Answer
Dec 29, 2015

#S = 2lw + 2lh + 2wh#

Explanation:

If we consider the structure of a box with length #l#, width #w#, and height #h#, we may note that it is formed from six rectangular faces. The bottom and top faces are rectangles with sides of length #l# and #w#. Two of the side faces have side lengths #l# and #h#. And the remaining two side faces have side lengths #w# and #h#.

As the area of a rectangle is the product of its side lengths, we can put this together to get the surface area #S# of the box as

#S = 2lw + 2lh + 2wh#