(i) In △′sAEC and ADB, we have
∠AEC=∠ADB=900 [∵CE⊥AB and BD⊥AC]
and, ∠EAC=∠DAB [Each equal to ∠A]
Therefore, by AA-criterion of similarity, we have
△AEC∼△ADB [Hence proved]
(ii) we have,
△AEC∼△ADB [AS proved above]
⇒ CABA=ECDB
⇒ CAAB=CEDB [Hence proved]