Answer:
80
Explanation:
Objective: Supplementary Angles.
Supplementary Angles are Angles that add up to 180.
In the problem, Two angles add up to 180. We don't know Angle A and we know Angle B.
Let set up the equation
Let x represent the measure of Angle A and x+20 represent the measure of Angle B
Combine Like Terms
Apply Basics Rules of Algebra
This means angle A measure 80 degrees