题目内容
如图,P是⊙O的直径CB延长线上的一点,PA是⊙O的切线,切点为A,∠P=20°,则∠ABP=______度.
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连接OA,如图所示:
∵PA为圆O的切线,
∴∠OAP=90°,又∠P=20°,
∴∠AOP=70°,
又∵OA=OB,
∴∠OAB=∠ABP,
∵∠AOP为△AOB的外角,∴∠AOP=∠OAB+∠ABP=2∠ABP,
∴∠ABP=
∠AOP=35°.
故答案为:35
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∵PA为圆O的切线,
∴∠OAP=90°,又∠P=20°,
∴∠AOP=70°,
又∵OA=OB,
∴∠OAB=∠ABP,
∵∠AOP为△AOB的外角,∴∠AOP=∠OAB+∠ABP=2∠ABP,
∴∠ABP=
1 |
2 |
故答案为:35
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