A helicopter is flying due west over level ground at a constant altitude of 222m and at a constant speed. An intelligent, stationary goat, which is due west of the helicopter, takes two measurements of the angle between the ground and the helicopter. The first measurement the goat makes is 15° and the second measurement, which he makes 1 minute later, is 75°. If the helicopter has not yet passed over the goat, how fast is the helicopter traveling in kilometers per hour? Find exact values in your solution without using a calculator. Clearly show and explain how you derived your solution.
Test soon, don't understand how to do this question, any help would be great. Thanks!