Answer 1

Proof:

(i) In ∆ ABC and ∆ ADC

AC = AC ...........(common)

AB = DC ............(given)

BC = AD ...........(given)

∴ ∆ ABC ≅ ∆ ADC ................(S.S.S. Axiom)

(ii) Hence ∠B = ∠D ...........(c.p.c.t.)

Hence proved.