If two triangles have the same side lengths, are they congruent?

In Euclidean geometry, if two triangles have the same side lengths, they are not necessarily congruent. This is because side lengths alone do not define a unique triangle. The congruence of two triangles is determined by the combination of their side lengths and angles. According to the Side-Side-Side (SSS) congruence criterion, if all three pairs of corresponding sides of two triangles are equal in length, then the triangles are congruent. It's important to consider both the side lengths and angles when determining the congruence of triangles.