Law of Sines
Law of Sines
In this applet we state the Law of Sines and give two proofs. The first proof uses less geometry and shows that the three ratios of a side length to the sine of its opposite angle are equal. The second proof uses more advanced results from geometry and shows that not only are these three ratios equal, but they are also equal to the diameter of the circumscribed circle. We also show how to solve these proportions to solve for a missing side length in the AAS or ASA cases, and for a missing angle in the SSA case, covering all 4 subcases of the SSA situation.