Question

Law of Cosines:
Please help me understand by showing work and explaining.
....
Find each measurement indicated. Round your answers to the nearest tenth.
**I will attach image**

Answer 1

i understand equations can vary from:
~ a^2=b^2+c^2-2(b)(c) cos(A)
~ b^2=a^2+c^2-2(a)(c) cos(B)
~ c^2=a^2+b^2-2(a)(b) cos(C)
i just do not understand how to use the equations.

Answer 2

the key is the angle and the side that you have

Answer 3

in this case what angle do you have ?