In triangle ABCABCABC, sides a=6a = 6a=6, b=7b = 7b=7, c=8c = 8c=8. By the Law of Cosines, c2=a2+b2−2abcos(C)c^2 = a^2 + b^2 - 2ab\\cos(C)c2=a2+b2−2abcos(C). Find cos(C)\\cos(C)cos(C).
frac36\\frac{3}{6}frac36
frac314\\frac{3}{14}frac314
frac312\\frac{3}{12}frac312
frac412\\frac{4}{12}frac412