A golfer hits an errant tee shot that lands in the rough A m

A golfer hits an errant tee shot that lands in the rough. A marker in the center of the fairway is 100 yards from the center of the green. While standing on the marker and facing the green, the golfer turns 110 degrees towards his ball. He then paces off 50 yards to his call. How far is the ball from the center of the green?

Solution

distance from ball to center of green = d
using law of cosines
d^2 = a^2 + b^2 - 2ab cos D
where a = 50
b = 100
D = 110 degrees
d^2 = 100^2 + 50^2 - 2(110)(50)cos 110
d = 127.52 yards, which seems reasonable