Answer: Choice D
∠DEF ≅ ∠ABC when BH = EJ, BI = EK, and HI = JK.
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Explanation:
Effectively what Ben is doing is ensuring that
are the three congruent corresponding sides. This is by construction. After those constructions, he would use SSS to prove the triangles congruent. Lastly, he can then say angle DEF is congruent to angle ABC due to CPCTC.
CPCTC = corresponding parts of congruent triangles are congruent.