已知∠AOB=70°,∠COD=30°,OE,OF分别平分∠AOC,∠BOD(1)绕O旋转∠COD,当射线OC,OD在∠AOB内部时,求∠EOF.(2)绕O旋转∠COD,当射线OC在∠AOB外时,求∠EOF
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已知∠AOB=70°,∠COD=30°,OE,OF分别平分∠AOC,∠BOD(1)绕O旋转∠COD,当射线OC,OD在∠AOB内部时,求∠EOF.(2)绕O旋转∠COD,当射线OC在∠AOB外时,求∠EOF
已知∠AOB=70°,∠COD=30°,OE,OF分别平分∠AOC,∠BOD
(1)绕O旋转∠COD,当射线OC,OD在∠AOB内部时,求∠EOF.
(2)绕O旋转∠COD,当射线OC在∠AOB外时,求∠EOF
已知∠AOB=70°,∠COD=30°,OE,OF分别平分∠AOC,∠BOD(1)绕O旋转∠COD,当射线OC,OD在∠AOB内部时,求∠EOF.(2)绕O旋转∠COD,当射线OC在∠AOB外时,求∠EOF
(1)
∠EOF=∠EOC+∠COD+∠DOF=1/2∠AOC+1/2∠BOD+∠COD
=1/2(∠AOB-∠COD)+∠COD
=1/2(∠AOB+∠COD)
=1/2(70°+30°)=50°
(2)
∠EOF=∠EOA+∠AOD+∠DOE=1/2∠AOC+∠AOD+1/2∠DOB
=1/2(∠AOC+2∠AOD+∠DOB)
=1/2(∠AOC+∠AOD +∠AOD+∠DOB)
=1/2(∠COD+∠AOB)
=1/2(30°+70°)=50°
1)
∠EOF=∠EOC+∠COD+∠DOF=1/2∠AOC+1/2∠BOD+∠COD
=1/2(∠AOB-∠COD)+∠COD
=1/2(∠AOB+∠COD)
=1/2(70°+30°)=50°
(2)
∠EOF=∠EOA+∠AOD+∠DOE=1/2∠AOC+∠AOD+1/2∠DOB
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1)
∠EOF=∠EOC+∠COD+∠DOF=1/2∠AOC+1/2∠BOD+∠COD
=1/2(∠AOB-∠COD)+∠COD
=1/2(∠AOB+∠COD)
=1/2(70°+30°)=50°
(2)
∠EOF=∠EOA+∠AOD+∠DOE=1/2∠AOC+∠AOD+1/2∠DOB
=1/2(∠AOC+2∠AOD+∠DOB)
=1/2(∠AOC+∠AOD +∠AOD+∠DOB)
=1/2(∠COD+∠AOB)
=1/2(30°+70°)=50° 分给我吧
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