Rob, Nicky and Troy are out on the water. Rob and Nicky are water skiing while Troy is parasailing (all from the same boat!). Rob's tow line is 15m long and Nicky's is 25 m long. The angle between the two tow lines is 70°. Troy, up in the air, is flying directly above Rob. If the angle of elevation from Nicky to Troy is 55°, how high above the water is Troy?
