Nimetön työkirja
Theorem 2.4.1. In a triangle, the sum of the measures of the interior angles is 180
We are now shoving that the sum of the measures of the interior angles of all triangles is 180. First we will show some examples of this statement and in the end we provide a formal proof for this theorem.
1. Example triangle ABC
2. Example triangle DEF
Proof of the theorem
Now we will make a formal proof so that we can see these two example triangles are not only exceptions but that the theorem 2.4.1. is always valid.