Answer:
∠DFE
Step-by-step explanation:
Complementary angles are angles that have a sum of 90°. Since there is a box on angle ∠CFB, we can infer that ∠CFE is also 90°. This is because the two are supplementary (equal 180°). Therefore, ∠DFE is the other part of ∠CFD that would complete the 90° pair.
