SSS means side side side so if 3 of the sides on each triangle are the same then its congruent Any time you see an A it stands for angle so you only have to learn the leters and then everything else is pretty straight forward
This is due to the all of the 90 degree angle which would make the rest of the line a would be another 90 degree angle Which are found on every line. This would make all of the lines parallel because it is a total of 180 degrees.
