A rectangular box with no cover, the length, width and height are 8 8 12cm respectively. Ants want to design the shortest route from point A to point B.
Let the rectangular frame be xcm in length, (x-4)cm in width and (13-x)/2cm in height. From the diagram,14-2× (13-x)/2 = 2 (x-4), and the length of the rectangular box is 9. 0? 6)