On a road trip you and your family stop a truck stop to take a break and to let your puppy Fido stretch. You notice that they have a triangular dog park that is fenced in on two sides. The third side of the field is formed by a creek. If the fences measure 150 feet and 98 feet, and the side along the creek is 172 feet, what are the measures of the angles made by the dog park?
cosine theorem can be used to calculate any of these three angles cosα=(150^2+172^2-98^2)/2*150*172