An open-top box is to be made by cutting small congruent squares from the corners of a 18-cm. by 18-cm. sheet of tin and bending up the sides. How large should the squares cut from the corners be to make the box hold as much as possible? [br][br]Drag the [b]black point[/b] to create boxes with various dimensions. Drag the slider to form the box.

[i]Developed for use with Thomas' Calculus, published by Pearson.[/i]