I cut off one corner of an empty box to form an open 'pocket', so that each of the length a, breadth b, and depth c, of the initial corner was a different whole number of centimetres, and the area of each face of the 'pocket' was also an integer.

What is the area of the open 4th side of the 'pocket', in terms of a,b, and c?

Charlie,

It's hard to say what's wanted here.

Try squaring the pairwise products of the three lengths {ab, ac, bc}, then comparing the sum of those three squares with the area of the open 4th side.

Edited on August 15, 2014, 1:25 am

Posted by broll on 2014-08-15 00:51:35