Question

如图两直线AB,CD相交于O.射线OE,OF分别是∠BOC,∠BOC的角平分线,（1）写出所有与∠AOC互补的角?

Answer 1

（1）∠COB,∠AOD

（2）∵OE,OF分别平分∠BOC和∠BOD

∴∠EOB=1/2∠COB,∠BOF=1/2∠BOD

∴ ∠EOF=∠EOB+∠BOF

=1/2∠COB+1/2∠BOD

=1/2∠COD

=90°