Question:
In ∆ABC and ∆DEF, it is given that ∠B = ∠E and ∠C = ∠F. In order that ∆ABC ≅ ∆DEF, we must have
(a) AB = DF
(b) AC = DE
(c) BC = EF
(d) ∠A = ∠D
Solution:
In order that $\triangle A B C \cong \triangle D E F$, we must have $\mathrm{BC}=\mathrm{EF}$.
Hence, the correct answer is option (c).