For problems 17 - 19, round answers to the nearest tenth, when necessary. 17) A fire truck has a 100 foot ladder whose base is 10 feet above the ground. A firefighter extends a ladder toward a burning building to reach a window 90 feet above the ground. Draw a diagram to represent this situation. At what angle should the firefighter set the ladder? 18) An airplane is flying at an altitude of 31,000 feet when it begins its decent for landing. If the runway is 104 miles away, at what angle does the airplane descend? 19) Different types of granular substances naturally settle at different angles when stored in cone-shaped piles. The angle 0 is called the angle of repose. When rock salt is stored in a cone-shaped pile 11 feet high, the diameter of the pile's base is about 34 feet. a) Find the angle of repose for rock salt. b) If another pile of rock salt is 15 feet high, what is the diameter of its base? And we should probably practice some problems from Section 13.3: Evaluate the function without using a calculator. 20) sin (-60#) 21) CSC 240 22) tan 23) COS 4 24) tan 330 25) csc (-405) 26) sin 13x 6 27) sec Ilx 3