Under which condition can the SSS congruence postulate be applied?

The SSS (Side-Side-Side) congruence postulate applies specifically when all three sides of one triangle are congruent to all three sides of another triangle. In essence, if you can prove that every side length of the first triangle is equal to the corresponding side length of the second triangle, the triangles are congruent.

This postulate does not rely on angles at all; it is purely based on the side lengths. Therefore, when you have three pairs of sides that are equal, you can conclude that the two triangles are equal in shape and size, making them congruent. This forms the basis for defining triangle similarity and congruence in geometric contexts.

In contrast, the other options refer to different congruence criteria that involve angles or partial side information but do not fully satisfy the SSS condition necessary for direct application of the SSS postulate.