Lesson Overview:

 

• Sine Law

• Cosine Law

 

Part A: Using Cosine Law to Solve a Triangle

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

This video shows solving the sides of a triangle using Cosine Law

 

 

 

 

 

 

 

 

 

 

This video shows how to solve for angles  of a triangle using Cosine Law

 

 

 

 

 

 

 

 

 

 

 

Example Problems Using Cosine Law:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Part B: Use Sine Law to Solve for Sides and Angles of Triangles 

You can use Sine Law to solve for triangles by knowing the ratio of one side to its corresponding angle is equal to another side with its corresponding angle.

 

 

 

 

 

 

 

 

 

 

 

 

Here is a video for solving for sides using Sine Law:

 

 

 

 

 

 

 

 

 

 

 

 

Here is a vudeo for solving for angles using Sine Law:

 

 

 

 

 

 

 

 

 

 

 

 

 

Example Problems Sine Law:

When solving ambiguous cases use sine law

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SAT Testing of Sine and Cosine Law:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Real World Application

 

 

 

 

 

 

 

 

 

 

Conclusion:

In conclusion, you can use Cosine Law to solve for triangles when you are lacking one side or one angle. Make sure you label your triangle appropriately and to remember that your calculator is your best friend. You can use Sine Law to solve for triangles by knowing two sides and one angle or two angles and one side. Simply plug in the appropriate numbers into the formula and solve. It is important to keep in mind that sometimes it may be necessary to use Sine Law along with Cosine Law to solve for a triangle.