LAW OF SINES GUIDE An oblique triangle is any triangle that is not a right triangle. There are methods of finding missing sides and missing angles in oblique triangles. One such method is called the Law of Sines, which relates the lengths of the sides of any triangle to the sines of its angles. Given the diagram: Note the lettering with side a across from ∠A, side b across from ∠B, and side c across from ∠C LAW OF SINES GUIDE