1、折叠后,∠A‘BC与∠ABC重合,
∴∠A’BC=∠ABC.
2、由折叠知:
∠A‘BC=1/2∠A’BA,∠A’BE=1/2∠A‘BD,
∴∠CBE=1/2(∠A’BA+A‘BD)=1/2×180°=90°,
∴BC⊥BE.