设∠AOB=X 那么∠COB=180-X OD是角AOB的角平分线。OE在角BOC内,角BOE=1/2角EOC 所以 ∠DOB=X/2 ∠EOB=(180-X)/3 ∠EOC=2(180-X)/3 ∠DOE=∠DOB+∠EOB...