Suppose a triangle has two sides of length 42 and 35, 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=422+352-2(42)(35)sin120°
sin 35
B.
sin42
120
=
b
OC.
2²=42²+35²-2(42)(35)cos120°
D. c=42+352(42)(35)cos120°