(2005•茂名)如图,梯形ABCD内接于⊙O,AB∥CD,AB为直径,DO平分∠ADC,则∠DAO的度数是( )![]() A.90° B.80° C.70° D.60° |
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(2006•临沂)已知△ABC,(1)如图1,若P点是∠ABC和∠ACB的角平分线的交点,则∠P=90°+![]() (2)如图2,若P点是∠ABC和外角∠ACE的角平分线的交点,则∠P=90°-∠A; (3)如图3,若P点是外角∠CBF和∠BCE的角平分线的交点,则∠P=90°- ![]() 上述说法正确的个数是( ) ![]() A.0个 B.1个 C.2个 D.3个 |
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(2005•常州)如图,已知AB∥CD,直线l分别交AB、CD于点E、F,EG平分∠BEF,若∠EFG=40°,则∠EGF的度数是( )![]() A.60° B.70° C.80° D.90° |
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(2005•成都)如图,直线AB、CD相交于O,OE⊥AB,那么下列结论错误的是( )![]() A.∠AOC与∠COE互为余角 B.∠BOD与∠COE互为余角 C.∠COE与∠BOE互为补角 D.∠AOC与∠BOD是对顶角 |
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(2013•玉林)若∠α=30°,则∠α的补角是( ) A.30° B.60° C.120° D.150° |
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(2007•西藏)已知∠A=40°,则∠A的补角等于( ) A.50° B.90° C.140° D.180° |
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(2005•哈尔滨)过一个钝角的顶点作这个角两边的垂线,若这两条垂线的夹角为40°,则此钝角为( ) A.140° B.160° C.120° D.110° |
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(2005•三明)一副三角板不能拼出的角的度数是(拼接要求:既不重叠又不留空隙)( ) A.75° B.105° C.120° D.125° |
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(2005•漳州)将一张纸按如图的方式折叠,BC、BD为折痕,则∠CBD的度数为( )![]() A.80° B.90° C.100° D.110° |
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(2005•漳州)如图,在A、B两座工厂之间要修建一条笔直的公路,从A地测得B地的走向是南偏东52°,现A、B两地要同时开工,若干天后公路准确对接,则B地所修公路的走向应该是( )![]() A.北偏西52° B.南偏东52° C.西偏北52° D.北偏西38° |
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