Given, ΔABE ≅ ΔACD
∴ AB = AC [By (CPCT)] ……………………………….(i)
And, AD = AE [By (CPCT)] ……………………………(ii)
(CPCT - Corresponding parts of congruent triangle)
In ΔADE and ΔABC, dividing equation (ii) by (i)
$ \dfrac{AD}{AB} = \dfrac{AE}{AC}$
$\angle A = \angle A $ [Common angle]
ΔADE ~ ΔABC [SAS similarity criterion]