For the law of cosines How am I supposed to know if I’m using SAS or SSS

SSS congruency is when you know that the two triangle you want to compare's sides have the same length. Since they have the same length, they are congruent. SAS congruency stands for "side, angle, side" and means that we have two triangles where we know two sides and the included angle are equal.

1) c 2143.6 cm

2) c 113.0 m

3) a 33.5 ft

4)   d 2 cm

5) c 20 mm

6) 180 in

7) d 120 ft