When using the law of sine it is used to determine the lengths of unknown angles and sides for both right triangles and oblique triangles. If you don’t already know what an oblique triangle is, it is simply a triangle with no right angles. The three different form of triangles are Scalene, Isosceles and Equilateral triangles. If asked to find the third angle of a triangle all that needs to be done is adding the two angles that are given to you and then subtracting that answer by 180. The formula that is used to find the unknown side of a triangle is the pythagorean formula which is a^2+b^2=c^2.