Question

In ∆ABC and ∆DEF, it is given that AB = DE and BC = EF. In order that ∆ABC ≅ ∆DEF, we must have
(a) ∠A = ∠D
(b) ∠B = ∠E
(c) ∠C = ∠F
(d) none of these

Answer 1

(b) $\angle B=\angle E$

In $△ABC\mathrm{and}△DEF,\mathrm{we}\mathrm{have}:$
AB = DE (Given)
BC = EF (Given)
In order that $△ABC\cong DEF$, we must have $\angle B=\angle E$.