Use the Law of Cosines to find the specified missing value, find c

Question

If C = 60°, a = 120 in, b = 66 in

Answer 1

Law of Cosines: c²  = a² + b² - 2ab cos C

c² = 120² + 66² -2 (120)(66) cos 60°

c²= 14,400 + 43,576 - 15,840 (.5)

c² = 57,976 - 7920

c² = 50,056

c = 223.73