Question

A 40 foot tree casts a shadow. The distance from the top of the tree to the tip of the shadow is 41 feet. How long of a shadow did the tree cast?

Answer 1

Let s represent the length of the shadow. By the Pythagorean theorem,
.. s^2 +40^2 = 41^2
.. s^2 = 1681 -1600 = 81
.. s = 9

The length of the shadow is 9 feet.