the horizontal leg (due east) = 1.5 km 
 
the vertical leg (due north) = 1.7 Km 
 
The hypotenuse is the distance from camp 
 
Use the Pythagorean theorem to find the length of the hypotenuse: 
 
waterfall's distance from camp = √(1.5² + 1.7²) = 2.3 km (to the nearest tenth)