Question

http://prntscr.com/arwka7
How do we find BA?

I know how to find A.

Struggling to find BA.

Answer 1

Law of cosine:\[c^2=a^2+b^2-2abcos(C)\]
Can you see which sides and angles all the variables associate to?

Answer 2

Oh, there you are. I closed my other question since it seemed some people were trying to solve for A when I only wanted BA. : )

How can we solve for BA if we don't have the angle?

@Bobo-i-bo

Answer 3

You have angle "C" though :P

Answer 4

You know the lengths of two sides and the angle inbetween. Therefore you can use the law of cosines to calculate the length of the third side

Answer 5

So the law of cosines is usually in the form:
\[a^2=b^2+c^2-2bccosA\]
You let b and c be the lengths of the two sides and A be the angle in the middle of the two sides. Then by using the formula above you can work out "a" which is the third side

Answer 6

Understood? :)

Answer 7

@Bobo-i-bo

I believe so : )

Answer 8

^_^