Explanation: We use the fact that the sum of all angles in a triangle is 180 degrees. Given any two angles and one non-included side (ie, AAS), we can apply the difference 180-angle1-angle2 to calculate the remaining, third angle. This allows us to consider the new angle and one of the given angles as including the given side, which is now a ASA problem and can be solved using the ASA Postulate. The rewrite is valid because we are not adding any new conditions to the premise "if two angles and a side are congruent."
