the triangles are congruent by the sss congruence theorem. which transformation(s) can map △lmn onto △lmn…

Brief Explanations:

Translation moves a figure without changing its orientation. Reflection flips a figure over a line. Rotation turns a figure around a point. Looking at the orientation of $\triangle LMN$ and $\triangle L'M'N'$, they are mirror - images of each other, so a reflection is needed. After reflection, a translation may be required to exactly map one triangle onto the other.

Answer:

reflection then translation