Given,
△ABE ≅ △ACD
Hence, AB = AC by CPCT. .....(1)
and AE = AD by CPCT.
⇒ AD = AE .....(2)
Dividing (2) by (1)
AD/AB = AE/AC ....(3)
In △ADE and △ABC
∠A = ∠A (common angle)
AD/AB = AE/AC from (3)
∴△ADE is similar to △ABC by SAS criterion.
Hence proved.