Respuesta :
Answer: (c) y = x and ΔABC ~ ΔFED
Step-by-step explanation:
If sin (y) = cos (x), then they are congruent angles. Thus, y = x
y = x ⇒ ∠A ≡ ∠ D
90° = 90° ⇒ ∠B ≡ ∠E
So, we can say that ΔABC ~ ΔDEF by the Angle-Angle (AA) Similarity Theorem.