Answer:
Alternate interior angles theorem
Step-by-step explanation:
DG // EF and GE is the transversal. So, alternate interior angles are congruent
Therefore, ∠HGD ≅ ∠HEF
DG // EF and DF is the transversal. So, alternate interior angles are congruent
Therefore, ∠HDG ≅ ∠HFE
