Answer:
|ST| = |FD|
Explanation:
Two triangles are aid to be congruent if all their three sides are equal to each other and their three angles are equal to each other. The congruent sides must not be in the same position especially when one triangle is the reflection of the other triangle.
Given that ΔTRS is congruent to ΔDEF. Also they have the same congruent part, hence:
|TR| = |DE|, |TS| = |DF|, |ST| = |FD|