Question

如图所示：∠xoy等于90度,点a,b分别在射线ox ,oy上移动,bc平分∠DBO,BC与∠OA

Answer 1

保持不变

∠ACB = ∠DBC - ∠BAC

= ∠DBO/2 - ∠BAO/2

= ( ∠DBO - ∠BAO ) / 2

= ∠AOB / 2 = 45°