[btmorex]

Well, I don't care about my math rep so... I don't get it.

You've listed 3 sides of a box. Does that mean that the "fourth" side is part of one of those 3 sides so a = b = c? Or are you asking for the orientation and relative length of the 3 sides such that the fourth side would maximize the area of the box?

[losvedir]

I think the question is asking something akin to "You have a box with width a, height b, and length c. What's the biggest shadow you can make?"

For example, if you think of the sun straight overhead, then the shadow will have area a*b. But if the sun moves over, then the shadow will grow by inclusion of some of the height of the box.

[sliverstorm]

You don't know how to represent a rectalinear shape with only 3 sides? Man, you really are behind.

... kidding :)

[nandemo]

The "3 sides" are the height, width and depth of the box.