Law of Cosine: Trigonometry Word Problem The longest side of a triangular lot is 21 meters. If another side of this lot is 17 meters and if the angle formed by thus side and third side is 95 degrees, how long is the third side?
Hint:  Draw a picture.  A 95 degree angle is a little more than right, and the longest side will be opposite it.  Label what you know.  Write down the law of cosines and identify the sides with the variables.  Solve.  What step is the problem?
law of cosine gives you
roots($[1 -2*17*\cos(95) -(21^2-17^2)]$)
$=10.9359$