We have the following:
Congruence criteria
The congruence criteria show us the minimum information necessary to affirm that two
triangles are congruent. They allow us to identify, with the available information, if two triangles
are or are not congruent with each other.
First congruence criterion: SSS
Two triangles are congruent if their three sides are respectively equal
Second congruence criterion: SAS
Two triangles are congruent if they have two sides and the angle between them respectively equal.
Third congruence criterion: ASA
Two triangles are congruent if they have one side and the two angles adjacent to that side respectively equal.
In this case we have that all the angles are equal, therefore, all their sides are equal, which means that it is an SSS congruence.