In Fig. 6.53, ∠1 = ∠2 and ∠3 = ∠4. (i) Is ΔADC ≅ ΔABC? Why? (ii) Show that AD = AB and CD = CB.
(i) Yes, by ASA
(ii) Yes, by CPCT: AD = AB and CD = CB
Given equal angles establish ASA congruence. Then CPCT proves equal sides.