Thread: Sine Law and Cosine Law

hey, I was just wondering when i would use sine law, opposed to cosine law and vice-versa.

Thanks!

You don't mean Law of Sines and Law of Cosines, right?


If you mean the law of sine, that is:

And the law of cosine:

Then you can use use either of them when you have a right triangle.

Which one depends on what you know, be it the opposite side, adjacent side, or the hypotenuse.

Originally Posted by jays-9

hey, I was just wondering when i would use sine law, opposed to cosine law and vice-versa.

Thanks!

You use the law of sines when you have two known angles and one known side in a triangle (AAS, ASA).

Law of Sines:

You use the law of cosines when you have two known sides and one known angle (triangle is SAS).