Two airplanes leave the same airport. One heads north, and the other heads east. After some time, the northbound airplane has traveled 72 kilometers. If the two airplanes are 97 kilometers apart, how far has the eastbound airplane traveled?
The two planes and the airport form a right triangle with hypotenuse 97 and one leg 72.
\(\text{other leg = eastbound plane} = \sqrt{97^2 - 72^2} = \boxed{65} \) km