# When can you use the law of sines and cosines?

##### 1 Answer

Oct 31, 2014

If you have one unknown in 3 sides and 1 angle of a triangle, then use the law of cosines to find the unknown.

If you have one unknown in 2 sides and 2 angles of a triangle, then use the law of sines to find the unknown.

I hope that this was helpful.