If three sides of one triangle are equal to the three sides of another triangle, then the two triangles are said to be congruent by SSS congruence.
For △ABC≅△DEF,
we have AB = DE, BC = EF and AC = DF in accordance with the definition of SSS congruence condition.
Also, ∠A=∠D,∠B=∠E and ∠C=∠F.