Question

In the figure, BC = CE and ∠1 = ∠2. Prove that ΔGCB ≅ ΔDCE.

Answer 1

In ΔGCB and ΔDCE and
∠1 + ∠GBC = ∠2 + ∠DEC = 180°
∠1 = ∠2 = 
⇒ ∠GBC = ∠DEC
BC = CE
∠GCB = ∠DCE =    ...(vertically opposite angles)
Therefore,
ΔGCB ≅ ΔDCE    ....(ASA criteria).