You can add, subtract, and multiply them. These three operations obey the rules for integers. There's a polynomial division algorithm that fills formally the same role as the usual division algorithm for integers. Polynomials added to, subtracted from, or multiplied by other polynomials yield only polynomials. Likewise, integers added to, subtracted from, or multiplied by other integers yield only integers.
I think it's ASA cuz since the lines indicate they are parallel, then you can find that the two interior angles are also congruent. Since two angles are the same with the side inbetween being the same, it's probably asa.