6.2 Law of Cosines

6.2: Law of Cosines

Derivation of the Law of Cosine 














Standard Form Law of Cosines:
-The Law of Cosines can be used to solve triangles that you have two sides and the angle between them (SAS)







Alternative Forms of Law of Cosines
-These forms of the Law of Cosine can be used to solve a triangle that you have all of the side lengths for, but no angles (SSS)







Example:

Find the angles of this triangle

Heron's Area Formula 

-Heron's Formula can be used to find the area of any triangle as long as you have the side lengths.

 where 

Example:

     s=49