哪些因素能够确定一个三角形与另一个相似？

There are three ways to determine similarity:

1. The $AA$ Postulate: Two triangles are similar iff 2 of their corresponding angles are congruent. We don't need the third one since the sum of the measures of the angles of a triangle equals $180^\circ$.

2. The $SSS$ Postulate: Two triangles are similar iff all of their corresponding sides are in proportion.

3. The $SAS$ Postulate: Two triangles are similar iff 2 of their corresponding sides are in proportion and the angle in between is congruent.