1. We can use the sine law since we have two angles and one of the angles had the side opposite it.
2. We can use the sine law because we have two angles, we can find the third angle in the triangle. This means we have all three angles. We now have two angles and one of the angles has the side opposite it.
3. We have a right triangle. We could use the sine law because we have the right angle and the hypotense. We have two sides and one angle.
4. We have two sides and the included angle. We cannot use the sine law. We would have to use the law of cosines to solve this problem.