In a parallelogram, opposite angles are congruent.
This means that the four angles of the parallelogram are:

Moreover, the sum of the interior angles of a polygon with n sides is 180(n-2). So, the sum of the interior angles of a parallelogram is 360.
This means

And since
, we have 
Just do 240 times 1/8 which is the same thing as 240/8, which is 30
A is independent while b is dependent.
This is because b is equal to a decreased by 2. Anytime a changes, then b does as well. B can only change in accordance with a.
Answer:
A
Step-by-step explanation:
