吾往矣
幼苗
共回答了18个问题采纳率:94.4% 举报
∵OD是∠AOB的平分线
∴∠AOD=∠DOB=1/2∠AOB
∵∠BOE=1/2∠EOC
∴∠BOE=1/3∠BOC
∵∠AOB+∠BOC=180°
∠DOE=∠DOB+∠BOE
=1/2∠AOB+1/3∠BOC
=1/2AOB+1/3(180°-∠AOB)
=1/2∠AOB-1/3∠AOB+60°
=1/6∠AOB+60°
∴1/6∠AOB+60°=72°
1/6∠AOB=12°
∠AOB=72°
∴∠AOD=1/2∠AOB=36°
1年前
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