Answer:
-0.05
Step-by-step explanation:
Apply the law of cosines. and solve for A

A = 79.04239272, or 79
Answer:
15. A
16. B
17. B
18. C
Step-by-step explanation:
The answer is 21.
I am not sure if you're looking for the answer, or the steps... get back to me foor help.