The shortest distance is a line from the spider to the fly. Since
the spider must crawl on the walls and cannot go through space,
the spider cannot take that path.
many problems, the shortest distance is the hypotenuse of a right
triangle. If you can find the lengths of the two legs, the Pythagorean
Theorem can be used to find the length of the hypotenuse.
variety of two-dimensional models are possible. Two are shown in
the solution. The right triangle is shown below.
is more than one solution to the original problem. (See the drawings.)
In one solution, the spider crosses the right wall; in the other,
the spider crosses the left wall. If there were an obstruction on
the right wall, the shortest path would cross the left wall.
different solutions are shown. In both of them the length of the path