Which transformation can verify congruence by turning one triangle 90?

A 90-degree rotation can be used to verify congruence between two triangles if one triangle can be rotated to perfectly overlap the other. This transformation involves turning the triangle around a specific point, typically the centroid or a vertex, by 90 degrees. If the two triangles coincide after this rotation, they are congruent. Additionally, other transformations such as reflection or translation may also be used in conjunction with rotation to establish congruence.