[問題] 數學考卷~所有三角形都是等腰三角形
B
過程如下: |＼
| ＼
| ＼F
有三個點A,B,C D| O／＼
做一條角A的平分線L, 和一條BC邊的中垂線M | ／ ＼
L和M相交於O (AO不需要和OF的向量相同) |／ E ＼
做OD⊥AB,OE⊥AC A ▇▇▇▇▇▇C
並連上BO和CO
1. 因為∠DAO=∠EAO ∠ODA=∠OEA AO=AO 所以△ADO=△AEO => 所以DO=EO AD=AE
2. 因為OF=OF BF=CF ∠BFO=∠CFO 所以△BFO=△CFO => BO=CO
3. 因為BO=CO DO=EO ∠ODB=∠OEC=90度 所以△BDO=△CEO => BD=CE
4. 因為AD=AE BD=CE 所以 AB=AC 因此 △ABC為等腰
哪裡錯了...
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