Since adjacent angles in a parallelogram are supplementary (they add up to 180°), and ∠B is double as ∠A, you have this equation:
∠A + 2·∠A = 180°
From that you can find: 3·∠A = 180° ⇒ ∠A = 60°.
It is C bc it is on the opposite side and on the outside
Answer:
do you want 4 steps or 7?
Step-by-step explanation:
