# Week 17-Sine Law

he trigonometric ratios for sine, cosine, and tangent are all very important for finding the lengths of the sides on right triangles and the angles of right triangles. How do you figure out missing angles and side lengths on triangles that are not right triangles though? You use the Sine Law or Cosine Law, depending on the numbers given to you. I will be explaining when to use the Sine law and how to use the Sine law.
The formula for the Sine Law is a/SinA = b/SinB = c/SinC. If the conditions of the problem are such that you will be able to use the Sine Law, you will only actually only 2/3 of this equation, however, the problem with dictate which thirds of this equation to use, so read the problem carefully. There is also an inverse of this equation: SinA/a = SinB/b = SinC/c. You would use the inverse for finding angles, and you would use the regular equation for finding the length of sides. The prerequisites to using this equation are: When when you have two angles and 1 of the lengths of the sides and you want to find another length of a side, or when you have the length of two sides, and you have one angle, and you want to find the degrees of the other angle that CORRESPONDS to one of the side lengths you ALREADY KNOW.