1)a parallelogram is a quadrilateral with opposite sides being parallel so the lines AB must equal CD or otherwise it wouldn't be a parallelogram
2)for a quadrilateral to be proven to be a parallelogram the consecutive angles has to be supplementary which means they add up to 180 or for example you could slice the parallelogram in half down the middle you could piece the two consecutive angles together to make 180 degrees
The anwser that I know of is 6x+2
The formula to find the measure of an interior angle is

, where

represents the number of sides in the polygon. In this problem,

would represent

.
Let's plug in the value for


Let's simplify that.

Now we know that the <span>measure of an interior angle of a regular three-sided polygon is 60</span>°.
Your answer would be B!Let me know if you have any questions regarding this problem!
Thanks!
-TetraFish