12.1 is the answer your question
Answer:
the other form of expression 11/6 is 1.83
A thousand ways you could solve this, but generally need to understand 3 concepts to do so
1. interior angles of triangle add up to 180 degrees
2. law of sines
3. law of cosines
my personal suggestion
determine what angle A is, then use law of sines in order to determine side c