This reminds me of the following:

Two teachers were asked how they would determine the height of a telephone pole. The math teacher said, "Use ration and proportion. Stand in the sun and measure your shadow. Now, Measure your height. Make that a fraction. Now, measure the length of the shadow of the telephone pole and that will allow you to determine the fourth property which will be the height of the pole." The English teacher said, "Cut down the pole and measure it." The (insert teacher of your choice here) teacher said, "Right. The math teacher gives me the height and the English teacher gives me the length."