What does
a=
&
c=
i already know the answer for b i just the answer for a& c

So check the picture below

let's find the missing side first, either b or c, say side "b"



so, b is about 37.37

now, let  us use the law of cosines, to find either angle A or C, hmmm say A





now, what's ∡C? well, all internal angles in a triangle are 180, thus ∡C picks up the slack from A and B, or 180 - A - B

The correct answer will be d. -4