Question

An open box is formed by cutting a 5 inch square measured from each corner and folding up the sides. If the volume of the carton is then 40 in3, what was the length of a side of the original square of cardboard?

Answer 1

Hello,
The height of the box is 5 in,
so the area of the bottom is a square of 40/5=8 (in²) and the side is
√8=2√2.
The length of a side of the original square of cardboard is 10+2√2≈12,828427... (in)