What can you conclude about the interior angles formed when two parrallel lines are cut by a transversal

In the pic I attatched, the interior angles are where the dashed arc is. They are on the interior of the parallel lines. We can conclude that the A and B add up to 180 and that they are supplementary angles. Same goes for the other set of A and B. We also know that angle B = the other angle B and the same goes for A.

We know that all of those angles added together=360. If A+B=180 then add another A and B in there---

A+B+A+B=180+180

2 (A+B) = 360