Law of cosines: a2 = b2 + c2 – 2bccos(A) What is the measure of Y to the nearest whole degree? 58° 64° 68° 73°

use law of cosine: 16²=17²+12²-2*17*12cosY
408cosY=17²+12²-16²=177
cosY=177/408
use your calculator to find Y: Y≈64