(1)图中的角有:∠AOD,∠AOC,∠AOE,∠DOC,∠DOE,∠DOB,∠COE,∠COB,∠EOB共有9个. 故答案是:9; (2)∵OD平分∠AOC,∴∠COD=∠AOD=∠AOC=×50°=25°, ∴∠COE=∠DOE-∠COD=90°-25°=65°, ∠BOE=180°-∠AOD-∠DOE=180°-25°-90°=65°; 故答案是:65°,65°; (3)结论:OE平分∠BOC. 理由:设∠AOC=2α, ∵OD平分∠AOC,∠AOC=2α, ∴∠AOD=∠COD=∠AOC=α, 又∵∠DOE=90° ∴∠COE=∠DOE-∠COD=90°-α. 又∵∠BOE=180°-∠DOE-∠AOD=180°-90°-α=90°-α, ∴∠COE=∠BOE,即OE平分∠BOC. |