Molly Mae

Well, while we wait here is a famous puzzle, apparently created by Henry Dudeney. In a room that it 12x12x30, there is a spider near the top of one of the smaller walls. She is one unit (foot or whatever) from the ceiling, and centered between the side walls. She sees a fly on the opposite wall, one unit from the floor and centered between the side walls. What is the shortest path that she can travel (on walls, ceiling, an/or floor) to get to the fly (which remains stationary the entire time)?

A: a straight line

@t_l: =P Care to elaborate further?