一、选择题(本大题10小题,每小题3分,共30分)
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A . 70°
B . 60°
C . 50°
D . 40°
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A . 2,3,5
B . 1,2,3
C . 2,3,4
D . 2,2,5
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A . x·x2 = x2
B . (xy)2 = xy2
C . (x2)3 = x6
D . x2 +x2 = x4
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A . 两点之间线段最短
B . 三角形两边之和大于第三边
C . 长方形的四个角都是直角
D . 三角形的稳定性
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A . 45°
B . 60°
C . 75°
D . 90°
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A . 65°
B . 65°或80°
C . 50°或65°
D . 40°
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9.
(2023八上·惠阳期中)
如图,在△ABC中,已知∠ABC和∠ACB的平分线相交于点D,过点D作EF∥BC交AB、AC于点E、F,若△AEF的周长为10,BC=6,则△ABC的周长为( )
![](//tikupic.21cnjy.com/2024/08/19/c3/2e/c32eb01dc9cf8fb2eb498c7aebcb8170_160x85.jpeg)
A . 16
B . 17
C . 18
D . 15
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10.
(2023八上·惠阳期中)
已知如图,等腰
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmo%3E%E2%96%B3%3C%2Fmo%3E%3Cmi+mathvariant%3D%22normal%22%3EA%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3EB%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3EC%3C%2Fmi%3E%3C%2Fmath%3E)
,
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi+mathvariant%3D%22normal%22%3EA%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3EB%3C%2Fmi%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmi+mathvariant%3D%22normal%22%3EA%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3EC%3C%2Fmi%3E%3C%2Fmath%3E)
,
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi+mathvariant%3D%22normal%22%3E%E2%88%A0%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3EB%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3EA%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3EC%3C%2Fmi%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmn%3E120%3C%2Fmn%3E%3Cmo%3E%C2%B0%3C%2Fmo%3E%3C%2Fmath%3E)
,
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi+mathvariant%3D%22normal%22%3EA%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3ED%3C%2Fmi%3E%3Cmo%3E%E2%8A%A5%3C%2Fmo%3E%3Cmi+mathvariant%3D%22normal%22%3EB%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3EC%3C%2Fmi%3E%3C%2Fmath%3E)
于点
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi+mathvariant%3D%22normal%22%3ED%3C%2Fmi%3E%3C%2Fmath%3E)
, 点
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi+mathvariant%3D%22normal%22%3EP%3C%2Fmi%3E%3C%2Fmath%3E)
是
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi+mathvariant%3D%22normal%22%3EB%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3EA%3C%2Fmi%3E%3C%2Fmath%3E)
延长线上一点,点
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi+mathvariant%3D%22normal%22%3EO%3C%2Fmi%3E%3C%2Fmath%3E)
是线段
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi+mathvariant%3D%22normal%22%3EA%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3ED%3C%2Fmi%3E%3C%2Fmath%3E)
上一点,
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi+mathvariant%3D%22normal%22%3EO%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3EP%3C%2Fmi%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmi+mathvariant%3D%22normal%22%3EO%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3EC%3C%2Fmi%3E%3C%2Fmath%3E)
, 下面的结论:
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi+mathvariant%3D%22normal%22%3E%E2%91%A0%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3E%E2%88%A0%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3EA%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3EP%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3EO%3C%2Fmi%3E%3Cmo%3E%2B%3C%2Fmo%3E%3Cmi+mathvariant%3D%22normal%22%3E%E2%88%A0%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3ED%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3EC%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3EO%3C%2Fmi%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmn%3E30%3C%2Fmn%3E%3Cmo%3E%C2%B0%3C%2Fmo%3E%3C%2Fmath%3E)
;
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi+mathvariant%3D%22normal%22%3E%E2%91%A1%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3E%E2%88%A0%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3EA%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3EP%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3EO%3C%2Fmi%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmi+mathvariant%3D%22normal%22%3E%E2%88%A0%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3ED%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3EC%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3EO%3C%2Fmi%3E%3C%2Fmath%3E)
;
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi+mathvariant%3D%22normal%22%3E%E2%91%A2%3C%2Fmi%3E%3Cmo%3E%E2%96%B3%3C%2Fmo%3E%3Cmi+mathvariant%3D%22normal%22%3EO%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3EP%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3EC%3C%2Fmi%3E%3C%2Fmath%3E)
是等边三角形;
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi+mathvariant%3D%22normal%22%3E%E2%91%A3%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3EA%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3EB%3C%2Fmi%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmi+mathvariant%3D%22normal%22%3EA%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3EO%3C%2Fmi%3E%3Cmo%3E%2B%3C%2Fmo%3E%3Cmi+mathvariant%3D%22normal%22%3EA%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3EP%3C%2Fmi%3E%3Cmo%3E.%3C%2Fmo%3E%3C%2Fmath%3E)
其中正确的是( )
![](//tikupic.21cnjy.com/2024/01/20/0f/5d/0f5d1bb04f32a51b89fb2d9bd54cf1da.png)
二、填空题(本大题共6小题,每题4分,共24分)
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15.
(2023八上·惠阳期中)
如图,OP平分∠AOB,∠AOP=15°,PC∥OA,PD⊥OA于点 D, PC=4,则PD=
![](//tikupic.21cnjy.com/2021/11/16/e0/4c/e04c9e192344969f587ee2a1419c6904.jpg)
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16.
(2023八上·惠阳期中)
如图,△ABC的面积为12,AB=AC,BC=4,AC的垂直平分线EF分别交AB,AC边于点E,F,若点D为BC边的中点,点P为线段EF上一动点,则△PCD周长的最小值为
.
![](//tikupic.21cnjy.com/2022/09/27/d0/05/d00528bd500c91f25baccc172d2db016.png)
三、解答题(一)(本大题3小题,每小题6分,共18分)
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(1)
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmsup%3E%3Cmrow%3E%3Cmrow%3E%3Cmo%3E%28%3C%2Fmo%3E%3Cmrow%3E%3Cmtext%3E%CF%80%3C%2Fmtext%3E%3Cmo%3E%E2%88%92%3C%2Fmo%3E%3Cmn%3E2%3C%2Fmn%3E%3Cmn%3E0%3C%2Fmn%3E%3Cmn%3E2%3C%2Fmn%3E%3Cmn%3E3%3C%2Fmn%3E%3C%2Fmrow%3E%3Cmo%3E%29%3C%2Fmo%3E%3C%2Fmrow%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmn%3E0%3C%2Fmn%3E%3C%2Fmrow%3E%3C%2Fmsup%3E%3Cmo%3E%E2%88%92%3C%2Fmo%3E%3Cmn%3E%7C%3C%2Fmn%3E%3Cmn%3E1%3C%2Fmn%3E%3Cmo%3E%E2%88%92%3C%2Fmo%3E%3Cmn%3E2%3C%2Fmn%3E%3Cmn%3E%7C%3C%2Fmn%3E%3Cmo%3E%2B%3C%2Fmo%3E%3Cmsup%3E%3Cmrow%3E%3Cmrow%3E%3Cmo%3E%28%3C%2Fmo%3E%3Cmrow%3E%3Cmo%3E%E2%88%92%3C%2Fmo%3E%3Cmn%3E2%3C%2Fmn%3E%3C%2Fmrow%3E%3Cmo%3E%29%3C%2Fmo%3E%3C%2Fmrow%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmn%3E3%3C%2Fmn%3E%3C%2Fmrow%3E%3C%2Fmsup%3E%3C%2Fmath%3E)
;
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(2)
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四、解答题(二)(本大题共3小题,每小题7分,共21分)
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20.
(2023八上·惠阳期中)
如图,在平面直角坐标系中,△ABC的顶点都在网格格点上,点A、B、C的坐标分别为(1,2)、(3,1)、(4,4)。
![](//tikupic.21cnjy.com/2024/08/19/86/45/86450419331f7e9695e521050e6a6d52_270x269.png)
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(1)
作出△ABC关于y轴对称的△
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmsub%3E%3Cmrow%3E%3Cmi%3EA%3C%2Fmi%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmn%3E1%3C%2Fmn%3E%3C%2Fmrow%3E%3C%2Fmsub%3E%3Cmsub%3E%3Cmrow%3E%3Cmi%3EB%3C%2Fmi%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmn%3E1%3C%2Fmn%3E%3C%2Fmrow%3E%3C%2Fmsub%3E%3Cmsub%3E%3Cmrow%3E%3Cmi%3EC%3C%2Fmi%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmn%3E1%3C%2Fmn%3E%3C%2Fmrow%3E%3C%2Fmsub%3E%3C%2Fmath%3E)
, △
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmsub%3E%3Cmrow%3E%3Cmi%3EA%3C%2Fmi%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmn%3E1%3C%2Fmn%3E%3C%2Fmrow%3E%3C%2Fmsub%3E%3Cmsub%3E%3Cmrow%3E%3Cmi%3EB%3C%2Fmi%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmn%3E1%3C%2Fmn%3E%3C%2Fmrow%3E%3C%2Fmsub%3E%3Cmsub%3E%3Cmrow%3E%3Cmi%3EC%3C%2Fmi%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmn%3E1%3C%2Fmn%3E%3C%2Fmrow%3E%3C%2Fmsub%3E%3C%2Fmath%3E)
各顶点坐标为
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmsub%3E%3Cmrow%3E%3Cmi%3EA%3C%2Fmi%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmn%3E1%3C%2Fmn%3E%3C%2Fmrow%3E%3C%2Fmsub%3E%3C%2Fmath%3E)
(
,
)、
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmsub%3E%3Cmrow%3E%3Cmi%3EB%3C%2Fmi%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmn%3E1%3C%2Fmn%3E%3C%2Fmrow%3E%3C%2Fmsub%3E%3C%2Fmath%3E)
(
,
)、
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmsub%3E%3Cmrow%3E%3Cmi%3EC%3C%2Fmi%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmn%3E1%3C%2Fmn%3E%3C%2Fmrow%3E%3C%2Fmsub%3E%3C%2Fmath%3E)
(
,
);
-
(2)
△
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmsub%3E%3Cmrow%3E%3Cmi%3EA%3C%2Fmi%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmn%3E1%3C%2Fmn%3E%3C%2Fmrow%3E%3C%2Fmsub%3E%3Cmsub%3E%3Cmrow%3E%3Cmi%3EB%3C%2Fmi%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmn%3E1%3C%2Fmn%3E%3C%2Fmrow%3E%3C%2Fmsub%3E%3Cmsub%3E%3Cmrow%3E%3Cmi%3EC%3C%2Fmi%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmn%3E1%3C%2Fmn%3E%3C%2Fmrow%3E%3C%2Fmsub%3E%3C%2Fmath%3E)
的面积为
;
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(3)
在x轴上作出一点P,使得PA+PC最短,点P的坐标为(,)。
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(1)
求证:
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmo%3E%E2%96%B3%3C%2Fmo%3E%3Cmi+mathvariant%3D%22normal%22%3EA%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3EC%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3EB%3C%2Fmi%3E%3C%2Fmath%3E)
≌
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmo%3E%E2%96%B3%3C%2Fmo%3E%3Cmi+mathvariant%3D%22normal%22%3EE%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3EB%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3ED%3C%2Fmi%3E%3C%2Fmath%3E)
;
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-
五、解答题(三)(本大题共3小题,每小题9分,共27分)
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-
(1)
求证:
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmo%3E%E2%96%B3%3C%2Fmo%3E%3Cmi+mathvariant%3D%22normal%22%3EA%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3EC%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3EE%3C%2Fmi%3E%3C%2Fmath%3E)
≌
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmo%3E%E2%96%B3%3C%2Fmo%3E%3Cmi+mathvariant%3D%22normal%22%3ED%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3EC%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3EB%3C%2Fmi%3E%3C%2Fmath%3E)
;
-
(2)
求证:
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi+mathvariant%3D%22normal%22%3E%E2%88%A0%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3EA%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3EO%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3ED%3C%2Fmi%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmn%3E60%3C%2Fmn%3E%3Cmo%3E%C2%B0%3C%2Fmo%3E%3C%2Fmath%3E)
;
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(3)
求证:
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmo%3E%E2%96%B3%3C%2Fmo%3E%3Cmi+mathvariant%3D%22normal%22%3EC%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3EM%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3EN%3C%2Fmi%3E%3C%2Fmath%3E)
是等边三角形.
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24.
(2023八上·惠阳期中)
如图1,点P、Q分别是等边△ABC边AB、BC上的动点(端点除外),点P从顶点A、点Q从顶点B同时出发,且它们的运动速度相同,连接AQ、CP交于点M。
![](//tikupic.21cnjy.com/2024/08/19/8c/ab/8cab2d56db7d5654f6a48728bb7ded64.jpeg)
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(2)
点点P、Q分别在AB、BC边上运动时,∠QMC变化吗?若变化,请说明理由;若不变,求出它的度数。
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(3)
如图2,若点P、Q在运动到终点后继续在射线AB、BC上运动,直线AQ、CP交点为M,则∠QMC变化吗?若变化,请说明理由;若不变,则求出它的度数。
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(2)
如图2,若C为x轴正半轴上一动点,以AC为直角边作等腰直角△ACD,∠ACD=90°,连接OD,求∠AOD的度数;
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(3)
如图3,过点A作y轴的垂线交y轴于E,F为x轴负半轴上一点,G在EF的延长线上,以EG为直角边作等腰Rt△EGH,过A作x轴垂线交EH于点M,连接FM,等式AM=FM+OF是否成立?若成立,请证明;若不成立,说明理由。