We already know that our square sheet of cardboard has sides of 6 foot length, and after cutting a square of side x from each one of the corners, the new length of our sides will be [tex]6-2x[/tex]. Now, once we fold the sides to create our box, both the length and the width are going to be equal to [tex]6-2x[/tex]; after all, we are creating of box out of a square. The height on the other hand will be one the sides that we cut to create our box; therefore, the height will be [tex]x[/tex].
To summarize, after folding, we will have a box of height = [tex]x[/tex], width= [tex]6-2x[/tex], and length=[tex]6-2x[/tex]
