作者:opple 时间:2023-01-03 阅读:()
求证:∠E=∠DFE.
证明:∵AB∥CD(已知),
∴∠B+∠=180°()
又∵∠B=∠D(已知)
∴∠D+∠=180°
∴()
∴∠E=∠DFE()
19.(本题8分)某车间的甲乙两名工人分别同时生产同种零件,他们一天生产零件y(个)与生产时间(小时)的函数关系如图所示.
(1)根据图象填空:
①甲、乙中,_______先完成一天的生产任务;
在生产过程中,_______因机器故障停止生产_______小时.
②当_______时,甲、乙两产的零件个数相等.
(2)谁在哪一段时间内的生产速度最快?
求该段时间内,他每小时生产零件的个数.
20.(本题10分)如图,Rt△ABC中,,D是AB上的一点,.过D作AB的垂线交AC于点E,CD交BE于点F.BE⊥CD吗?
请说明理由。
B卷(50分)
一、填空题(每小题4分,共20分)
21.已知m2-mn=21,mn-n2=-15,则代数式的值是________。
22.△ABC的三边a、b、c,化简:
23.若的展开式中不含x2的项,
则a的值为。
24.如图,若AB∥CD,AB∥EF,那么∠BCE与∠B,
∠E的关系为__________________。
25.如图,C为线段AE上一动点(不与点A、E重合),在AE同侧分别作等边三角形ABC和等边三角形CDE,AD与BE交于点O,AD与BC交于点M,BE与CD交于点N,连结MN,以下五个结论,一定成立的有_________
①AD=BE;②AM=BN;③MN∥AE;
④DM=DE;⑤∠AOB=60
二、解答题:(本题8分)
26.已知,如图,在△ABC中,∠ACB=90°,AC=BC,直线MN经
过点C,且AD⊥MN于点D,BE⊥MN于点E;试猜测线段DE、
AD、BE之间的数量关系,并说明理由。
三、解答题:(共10分)
27.如图a是一个长为2m、宽为2n的长方形,沿图中虚线用剪刀均分成四块小长方形,然后按图b的形状拼成一个正方形。
图a图b
(1)你认为图b中的阴影部分的正方形的边长
等于。(1分)
(2)请求出图b中阴影部分的面积。(1分)
(3)观察图b你能写出下列三个代数式之间的等量关系吗?(4分)
代数式:
(4)根据(3)题中的等量关系,解决如下问题:若,求的值。(4分)
四、解答题:(共12分)
28.如图①,△ABC≌△DEF,将△ABC和△DEF的顶点B与顶点E重合放置。
(1)把△DEF和△ABC放置到如图②位置时,点B(E)、C、D在同一直线上,点B(E)、F、A在同一直线上,AC与FD相交于点O,则∠AFD与∠DCA的数量关系是.(3分)
(2)当把△DEF和△ABC放置如图③位置时,连接AF和DC,(1)中的结论还成立吗?请说明理由.(6分)
(3)在图③中,连接BO、AD,猜想BO与AD之间有怎样的位置关系?
(直接写出结论,无需证明)(3分)
成都铁中2012-(上)初级9月入学检测
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篇7:八年级英语上册测试题
一、选择填空(15分)
( )1. I usually go to the movies__ a month.
A. twice B. twice time C. two times D. twice times
( )2. _____do they play football? --Always.
A. How soon B. How much C . How many D. How often
( )3. His mother wants him _____ at home today.
A. stays B. stayed C. to stay D. staying
( )4. Here _____ the results _____ the students activity survey.
A. is, with B. are, of C. is, of D. are, with
( )5. _____ Dashan is from Canada ,_____he can speak Chinese very well.
A. Although; but B. Although; / C. Although; so D. /; so
( )6.Good _____habits help me get good grades.
A. studying B. study C. studied D. studies
( )7. I think doing sports is _____our health.
A. good at B. bad for C. good for D. good to
( )8. Is her watch _______ yours or different?
A. the same B. the same as C. same as D. the same to
( )9. My mother is out, so I have to _____ my young sister at home.
A. look at B. look after C. look for D. look over
( )10.Let us talk about the difference ______Chinese and English names.
A. on B. of C. between D. with
( )11.What ________ she usually _______ after class?
A. is; doing B. does; do C. does; does D. is; do
( )12. Kate hardly ever does her homework on weekends, ________?
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