Question

Please help with this question!! Solve for C.

Answer 1

C = 118.6

Explanation:

Law of cosines:

c² = a² + b² -2ab*cos(C)

Where a, b and c are the sides opposite to angles A, B and C

⇒ 37² = 23² + 20² - 2(23)(20)*cos(C)

⇒ 2(23)(20)*cos(C) = 23² + 20² - 37²

⇒ 920*cos(C) = 529 + 400 - 1369

⇒ 920*cos(C) = -440

⇒ cos(C) = -440/920

⇒ C = cos⁻¹(-440/920)

C = 118.6