Answer:
I would identify the proportions of the corresponding sides, because that would allow you to identify whether or not the triangles are similar. You could also identify if two triangles are similar using
-SSS (side-side-side) which would tell you if all three corresponding sides are congruent
-SAS (side-angle-side) which would tell you if two sides and the angle between them are congruent
-ASA (angle-side-angle) which would tell you the two angles and the side between them are congruent
-AAS (angle-angle-side) which would tell you if two angles and a non-included side are congruent. You triangles may have all of these, or just one, but it will help you identify the similarity between triangles