Triangle Angle Sum

The sum of the three angles in any triangle sum to 180 degrees. The importance of this fact in Geometry cannot be emphasized enough. The triangle angle sum theorem is used in almost every missing angle problem, in the exterior angle theorem, and in the polygon angle sum formula.

Videos

$How to apply the triangle angle sum theorem.$
$How to apply the triangle angle sum theorem when you need to find missing angles.$
$How to apply the triangle angle sum theorem when you need to solve for x.$