Suppose a triangle has two sides of length 33 and 37, and that the angle between these two sides is 120°. Which equation should you solve to find the length of the third side of the triangle?
A. c²=33²+37²-2(33)(37)cos 120°
B. c=33+37-2(33)(37)cos 120°
C. c²=33²+37²-2(33)(37)sin 120°
D. sin 33/120 = sin 37/b