One the first set, #1 figure, notice we have two angle tickmarks, so those angles are equal, however, notice at segment AB, is at the border of both triangles, so AB is just the same length for ∡ABC as it's for ∡ADB.
so, we have an Angle, then a Side, and then an Angle, so they're congruent by ASA.
now, on the 2nd set, #2 figure, we have an angle tickmark and a side tickmark, hmmmmm but notice angles 1 and 2, they're just across from each other at that junction, therefore, angles 1 and 2 are vertical angles adn therefore are also equal.
so, we have a Side, then an Angle and then another Side, the triangles are congruent by SAS.
