We have the following:
AA stands for "angle, angle" and it means that triangles have two of their angles equal.
SAS means "side, angle, side" and it means that we have two triangles where:
• the relationship between two sides is the same as the relationship between two other sides
,
• and we also know that the included angles are equal.
SSS means "side, side, side" and it means that we have two triangles with the three pairs of corresponding sides in the same proportion.
15/5 = 3
12/4 = 3
Sides proportional
Therefore, the answer is B. SAS because the two side are proportional and the included angle is congruent