In the given figure, ∠1=∠2 and ACBD=CBCE.
Prove that ΔACB∼ΔDCE.
∠1 = ∠2 (Given)
AC/BD=CB/CE ⇒ AC/CB=BD/CE (Given)
Also, ∠2 = ∠1
Thus, AC/CB=BD/CE and ∠2 = ∠1
Therefore, by SAS similarity criterion ΔACB ~ ΔDCE