如图在△abc中已知ad⊥于bc垂足为d,ae bf分别是∠bac ∠abc的平分线ae与bf交于点o(1)当∠bac=50°∠c=70°求∠aed,∠aob(2)当c=a时求∠aob
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![如图在△abc中已知ad⊥于bc垂足为d,ae bf分别是∠bac ∠abc的平分线ae与bf交于点o(1)当∠bac=50°∠c=70°求∠aed,∠aob(2)当c=a时求∠aob](/uploads/image/z/12514493-29-3.jpg?t=%E5%A6%82%E5%9B%BE%E5%9C%A8%E2%96%B3abc%E4%B8%AD%E5%B7%B2%E7%9F%A5ad%E2%8A%A5%E4%BA%8Ebc%E5%9E%82%E8%B6%B3%E4%B8%BAd%2Cae+bf%E5%88%86%E5%88%AB%E6%98%AF%E2%88%A0bac+%E2%88%A0abc%E7%9A%84%E5%B9%B3%E5%88%86%E7%BA%BFae%E4%B8%8Ebf%E4%BA%A4%E4%BA%8E%E7%82%B9o%EF%BC%881%EF%BC%89%E5%BD%93%E2%88%A0bac%3D50%C2%B0%E2%88%A0c%3D70%C2%B0%E6%B1%82%E2%88%A0aed%2C%E2%88%A0aob%EF%BC%882%29%E5%BD%93c%3Da%E6%97%B6%E6%B1%82%E2%88%A0aob)
如图在△abc中已知ad⊥于bc垂足为d,ae bf分别是∠bac ∠abc的平分线ae与bf交于点o(1)当∠bac=50°∠c=70°求∠aed,∠aob(2)当c=a时求∠aob
如图在△abc中已知ad⊥于bc垂足为d,ae bf分别是∠bac ∠abc的平分线ae与bf交于点o
(1)当∠bac=50°∠c=70°求∠aed,∠aob(2)当c=a时求∠aob
如图在△abc中已知ad⊥于bc垂足为d,ae bf分别是∠bac ∠abc的平分线ae与bf交于点o(1)当∠bac=50°∠c=70°求∠aed,∠aob(2)当c=a时求∠aob
(1)∵AE平分∠BAC,
∴∠BAE=1/2∠BAC=25°,
又∵∠ABC=180°-∠BAC-∠C=60°,
∴∠AED=∠ABD+∠BAE=60+25=85°;
∵∠OAB=1/2∠BAC=25°,∠OBA=1/2∠ABC=30°,
∴∠AOB=180°-(∠OAB+∠OBA)=125°
(2)∵∠C=a,
∴∠CAB+∠BAC=180°-a,
∴∠OAB+∠OBA=1/2(∠CAB+∠BAC)=90°-1/2a,
∴∠AOB=180°-(∠OAB+∠OBA)=90°+1/2a
(1)∵AE平分∠BAC,
∴∠BAE = 1/2∠BAC = 25°
另一个∵∠ABC = 180° - ∠BAC-∠C = 60°,
∵∠OAB = 1/2∠BAC = 25°,∠OBA = 1/2∠ABC = 30°
∴∠AOB = 180° - (∠OAB +∠OB...
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(1)∵AE平分∠BAC,
∴∠BAE = 1/2∠BAC = 25°
另一个∵∠ABC = 180° - ∠BAC-∠C = 60°,
∵∠OAB = 1/2∠BAC = 25°,∠OBA = 1/2∠ABC = 30°
∴∠AOB = 180° - (∠OAB +∠OBA)= 125°
(2)∵∠C = A,
∴∠CAB +∠BAC = 180° - ,
∴∠OAB +∠OBA = 1/2(∠CAB +∠BAC)= 90°-1/2a,
∴∠AOB = 180° - (∠OAB +∠ OBA)= 90°+ 1/2A
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