What is Law of the sine?

The law of sines is a statement about arbitrary triangles in the plane.

The law of sines states that in any right triangle, the ratio of the opposite side length to the length of the hypotenuse (relative to an acute angle) is always relative to the size of the angle. Put more simply, it means that if you take the sine of an angle, the value will be equal to the length of the opposite side divided by the length of the hypotenuse. The practical application of this is when you know the length of only one side and the measure of one angle (other than the right angle) you can determine the other sides and the remaining angle.
The law of sines states that in any right triangle, the ratio of the opposite side length to the length of the hypotenuse (relative to an acute angle) is always relative to the size of the angle. Put more simply, it means that if you take the sin of an angle, the value will be equal to the length of the opposite side divided by the length of the hypotenuse. The practical application of this is when you know the length of only one side and the measure of one angle