Question

Use the law of cosines to find the length of a

Answer 1

Answer:

Step-by-step explanation:

You don't need the Law of Cosines, the Law of sines if what you need. You can't use the Law of Cosines because in order to find side a, you would need the length of side c and you don't have it. Using the Law of Sines is appropriate, knowing that angle B = 55:

$\frac{sin55}{175}=\frac{sin42}{a}$ and solving for a:

$a=\frac{175sin42}{sin55}$ so

a = 143.0