The following are theorems associated with the angles of a triangle. You will use each of these concepts to find missing angle measures and eventually construct proofs. Remember that theorems and postulates are relationships that have been proven. Copy down each theorem, then view the proofs of each theorem.
You will now be applying the theorems from above. Copy down the examples in your notes. If you need extra instruction view the video links.
In the following you will practice using the triangle sum theorem in Khan Academy. Make sure to use the videos and hints if needed.