On a 180-yard hole, a golfer hits the ball 175 yards, 3 degrees off-line. How far is the ball from the cup?
You can set this up using the law of cosines.
Recall that the law of cosines is c2 = a2 + b2 -2ab cos θ where θ is the angle included between sides of lengths a and b while c is the remaining side's length.
In this case we have a = 175, b = 180, and θ = 3°
So the final distance is
c = √(1752 + 1802 - 2·175·180 cos 3°) = 10.6 yards