We can use the sine rule to
1.Find a side when it is opposite and a known angle and we also have another side opposite another angle, both of which we know: 

2. Find an angle when it is opposite an known side and we also have another side opposite another angle, both of which we know


To find the side as in 1 we start by labelling the sides a,b,c and the angles A,B,C with sides opposite their respective angles as shown. 

To find an angle we start by labelling the sides a,b,c and the angles A,B,C with sides opposite their respective angles as shown. 