Essential Question: How do i use triangle sum properties to find unknown values?

In order to find the unknown value of the triangle sum, the measures of the interior angles of that triangle has to equal  180. To determine whether its equal to 180, you use the numbers in the equation given to follow though. When trying to find the unknown number of any triangle you have to use the Triangle Angle Sum Theorem to solve for it. The Triangle Angle Sum Theorem states that a right triangle equals 180. After you put the equation you need to plug in the numbers you get into the equation. 

 

Video:

http://www.winpossible.com/lessons/Geometry_Triangle_Angle-Sum_Theorem.html