Exercise 55 Page 478

n/h=h/■ Since we are given a right triangle, we can use the Right Triangle Altitude Theorem.

Let's compare the theorem to the known segment names of our figure. BD/CD=CD/■ ⇔ n/h=h/■ In our case, n is a partial segment of the hypotenuse and h is the altitude. We can complete our proportion using the length of the other partial segment of the hypotenuse. Looking at the given figure, we can see that this length is m.

Let's complete the given proportion! n/h=h/m