It is triangle congruence theorem

SAS (Side-Angle-Side) Congruence Postulate If the two sides and an included angle of one triangle are congruent to thecorresponding two sides and the included angle of another triangle, then the trianglesare congruent.

ASA (Angle-Side-Angle) Congruence Postulate If the two angles and the included side of one triangle are congruent to thecorresponding two angles and an included side of another triangle, then the trianglesare congruent

SSS (Side-Side-Side) Congruence Postulate If the three sides of one triangle are congruent to the three sides of anothertriangle, then the triangles are congruent

AAS (Angle-Angle-Side) Congruence TheoremIf two angles and a non-included side of one triangle are congruent to thecorresponding two angles and a non-included side of another triangle, then thetriangles are congruent.

LL Congruence Theorem If the legs of one right triangle are congruent to the legs of another right triangle,then the triangles are congruent

LA (leg-acute angle) Congruence Theorem If a leg and an acute angle of one right triangle are congruent to a leg and anacute angle of another right triangle, then the triangles are congruent.