最新初二下学期数学经典题型优秀名师资料.docx
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最新初二下学期数学经典题型优秀名师资料
初二下学期数学经典题型
数据整理典型题
一、选择题:
(每小题3分,共30分)
2.实验中学七年级进行了一次数学测验,参考人数共540人,为了了解这次数学测验成绩,下列所抽取的样本中较为合理的是()
A.抽取前100名同学的数学成绩
B.抽取后100名同学的数学成绩
C.抽取
(1)、
(2)两班同学的数学成绩
D.抽取各班学号为3号的倍数的同学的数学成绩
4.统计得到的一组数据有80个,其中最大值为141,最小值为50,取组距为10,可以分成()
A.10组B.9组C.8组D.7组
5.在频数分布直方图中,各小长方形的高等于相应组的()A.组距B.组数C.频数D.频率
8.一个扇形统计图中,扇形A、B、C、D的面积之比为2?
3?
3?
4,则最大扇形的圆心角为()
A.80?
B.100?
C.120?
D.150?
10.某公司的生产量在七个月之内的增长变化情况如图所示,从图上看,下列结论不正确的是()
A.2,6月生产量增长率逐月减少
B.7月份生产量的增长率开始回升
C.这七个月中,每月生产量不断上涨
D.这七个月中,生产量有上涨有下跌
二、填空题(每题3分,共计30分)
11.要考察的全体对象称为,样本中个体的数目称为.13.某超市对今年前两个季度每月销售总量进行统计,为了更清楚地看出销售总量的总趋势是上升还是下降,应选用统计图来描述数据.14.在一个扇形统计图中,有一个扇形占整个圆的30%,则这个扇形圆心角是.
15.有一些乒乓球,不知其数量,先取6个作了标记,把它们放回袋中,混合均creditmanagement:
clearconditionsandrequirementsforloanextension.(10)recoveryanddisposal:
1terminayear(including)withintheloan,inadditiontothemonthlyinterestpayment,dueinprincipalrepaymentoptions,youcanalsoselectamatchingservice,equalprincipalrepaymentmethod;2,ClientManagerafterreceivingandreviewingearlyrepaymentoftheapplicationshallbesubmittedtotheheadoftheMarketingDepartmentforreview,processingthroughtheexaminationandapprovalproceduresofrepayment.(11)definedtheoffence.Third,incaseofproblemsduringtheimplementationprocess,pleasecontactHeaddivision.Annex:
qiluBankpersonalloansguaranteedmanagementqiluBankboFebruary1,11keywords:
retailbankingguaranteeloanmanagementofqiluBank'sOfficeissuedonFebruary1,2011Proofreading:
LiuDebaoAnnex:
qiluBankpersonalloansguaranteedManagementchapterIGeneralprovisionsarticletopromotepersonalloansguaranteedbusinessdevelopment,standardizedlendingpractices,accordingtothePeople'sRepublicofChinaoncommercialbanksandtheChinaBankingRegulatoryCommissionandotherlawsandregulationsoftheinterimmeasuresfortheadministrationofpersonalloans,thesemeasuresareformulated.IndividualguaranteearticleIIisanaturalorlegalpersonunitstoprovidesecurityfortheloan,granted
匀后又取了20个,发现含有两个做标记的,可以估计这袋乒乓球有个.16.已知一组数据都是整数,其中最大值是242,最小数据是198,若把这组数据分成9个小组,则组距是.
17.将收集到的40个数据进行整理分组,已知落在某一区间内的频数是5,则该组的频率是.
18.某商场为了解本商场的服务质量,随机调查了来本商场
购物的100名顾客,调查的结果如图所示,根据图中给出的
信息可知,这100•名顾客中对该商场的服务
质量表示不满意的有人.
认识概率典型题
1((2012?
肇庆)袋子中装有4个黑球2个白球,这些球除了颜色外都相同,从袋子中随机摸出一个球,则摸到黑球的概率是()
1112A(B(C(D(6233
12(从n张互不相同的普通扑克牌中任意抽取一张,抽到黑桃K的概率为,则n5为:
()
A(54B(52C(10D(5
3(从1、l、2三个数中任取一个,作为一次函数y=kx+3的k值,则所得一次函数中y随x的增大而增大的概率是__________(
4(有一个正十二面体,12个面上分别写有1,12这12个整数,投掷这个正十二面体一次,向上一面的数字是3的倍数或4的倍数的概率是__________(
4(对于平面内任意一个四边形ABCD,现从以下四个关系式:
?
AB=CD;?
AD=BC;?
AB?
CD;?
A=C中任取两个作为条件,能够得出这个四边形,,
ABCD是平行四边形的概率是__________(
平行四边形的性质
二、课中强化(10分钟训练)
1.如图3,在平行四边形ABCD中,下列各式不一定正确的是()
A.?
1+?
2=180?
B.?
2+?
3=180?
C.?
3+?
4=180?
D.?
2+?
4=180?
creditmanagement:
clearconditionsandrequirementsforloanextension.(10)recoveryanddisposal:
1terminayear(including)withintheloan,inadditiontothemonthlyinterestpayment,dueinprincipalrepaymentoptions,youcanalsoselectamatchingservice,equalprincipalrepaymentmethod;2,ClientManagerafterreceivingandreviewingearlyrepaymentoftheapplicationshallbesubmittedtotheheadoftheMarketingDepartmentforreview,processingthroughtheexaminationandapprovalproceduresofrepayment.(11)definedtheoffence.Third,incaseofproblemsduringtheimplementationprocess,pleasecontactHeaddivision.Annex:
qiluBankpersonalloansguaranteedmanagementqiluBankboFebruary1,11keywords:
retailbankingguaranteeloanmanagementofqiluBank'sOfficeissuedonFebruary1,2011Proofreading:
LiuDebaoAnnex:
qiluBankpersonalloansguaranteedManagementchapterIGeneralprovisionsarticletopromotepersonalloansguaranteedbusinessdevelopment,standardizedlendingpractices,accordingtothePeople'sRepublicofChinaoncommercialbanksandtheChinaBankingRegulatoryCommissionandotherlawsandregulationsoftheinterimmeasuresfortheadministrationofpersonalloans,thesemeasuresareformulated.IndividualguaranteearticleIIisanaturalorlegalpersonunitstoprovidesecurityfortheloan,granted
图3图4图5
2.如图4,ABCD的周长为16cm,AC、BD相交于点O,OE?
AC交AD于E,则?
DCE
的周长为()
A.4cmB.6cmC.8cmD.10cm
3.如图5,ABCD中,EF过对角线的交点O,如果AB=4cm,AD=3cm,OF=1cm,则四边形
BCFE的周长为__________________.
4.如图6,已知在平行四边形ABCD中,AB=4cm,AD=7cm,?
ABC的平分线交AD于点E,
交CD的延长线于点F,则DF=_____________cm.
图6图7
5.如图7,在平行四边形ABCD中,点E、F在对角线BD上,且BE=DF,求证:
AE=CF.
6.在ABCD中,AE?
BC于E,AF?
CD于F,BE=2cm,DF=3cm,?
EAF=60?
试求CF的长.(自
己画图)
三、课后巩固(30分钟训练)
1.ABCD中,?
A比?
B大20?
则?
C的度数为()
A.60?
B.80?
C.100?
D.120?
2.以A、B、C三点为平行四边形的三个顶点,作形状不同的平行四边形,一共可以作()
A.0个或3个B.2个C.3个D.4个
3.如图9所示,在ABCD中,对角线AC、BD交于点O,下列式子中一定成立的是()
A.AC?
BDB.OA=OCC.AC=BDD.AO=ODcreditmanagement:
clearconditionsandrequirementsforloanextension.(10)recoveryanddisposal:
1terminayear(including)withintheloan,inadditiontothemonthlyinterestpayment,dueinprincipalrepaymentoptions,youcanalsoselectamatchingservice,equalprincipalrepaymentmethod;2,ClientManagerafterreceivingandreviewingearlyrepaymentoftheapplicationshallbesubmittedtotheheadoftheMarketingDepartmentforreview,processingthroughtheexaminationandapprovalproceduresofrepayment.(11)definedtheoffence.Third,incaseofproblemsduringtheimplementationprocess,pleasecontactHeaddivision.Annex:
qiluBankpersonalloansguaranteedmanagementqiluBankboFebruary1,11keywords:
retailbankingguaranteeloanmanagementofqiluBank'sOfficeissuedonFebruary1,2011Proofreading:
LiuDebaoAnnex:
qiluBankpersonalloansguaranteedManagementchapterIGeneralprovisionsarticletopromotepersonalloansguaranteedbusinessdevelopment,standardizedlendingpractices,accordingtothePeople'sRepublicofChinaoncommercialbanksandtheChinaBankingRegulatoryCommissionandotherlawsandregulationsoftheinterimmeasuresfortheadministrationofpersonalloans,thesemeasuresareformulated.IndividualguaranteearticleIIisanaturalorlegalpersonunitstoprovidesecurityfortheloan,granted
图9图10图114.如图10,平行四边形ABCD中,对角线AC、BD相交于点O,将?
AOD平移至?
BEC的位置,则图中与OA相等的其他线段有()
A.1条B.2条C.3条D.4条5.如图11,在平行四边形ABCD中,EF?
AB,GH?
AD,EF与GH交于点O,则该图中的平行四边形的个数共有()
A.7个B.8个C.9个D.11个6.如图12,平行四边形ABCD中,AE?
BD,CF?
BD,垂足分别为E、F,求证:
?
BAE=?
DCF.
图12
7、如图13所示,已知平行四边形ABCD中,E、F分别是BC和AD上的点,且BE=DF.
求证:
?
ABE?
?
CDF.
图138.如图14,已知四边形ABCD是平行四边形,?
BCD的平分线CF交边AB于F,?
ADC的平分线DG交边AB于G.
(1)求证:
AF=GB;
(2)请你在已知条件的基础上再添加一个条件,使得?
EFG是等腰直角三角形,并说明理
由.
creditmanagement:
clearconditionsandrequirementsforloanextension.(10)recoveryanddisposal:
1terminayear(including)withintheloan,inadditiontothemonthlyinterestpayment,dueinprincipalrepaymentoptions,youcanalsoselectamatchingservice,equalprincipalrepaymentmethod;2,ClientManagerafterreceivingandreviewingearlyrepaymentoftheapplicationshallbesubmittedtotheheadoftheMarketingDepartmentforreview,processingthroughtheexaminationandapprovalproceduresofrepayment.(11)definedtheoffence.Third,incaseofproblemsduringtheimplementationprocess,pleasecontactHeaddivision.Annex:
qiluBankpersonalloansguaranteedmanagementqiluBankboFebruary1,11keywords:
retailbankingguaranteeloanmanagementofqiluBank'sOfficeissuedonFebruary1,2011Proofreading:
LiuDebaoAnnex:
qiluBankpersonalloansguaranteedManagementchapterIGeneralprovisionsarticletopromotepersonalloansguaranteedbusinessdevelopment,standardizedlendingpractices,accordingtothePeople'sRepublicofChinaoncommercialbanksandtheChinaBankingRegulatoryCommissionandotherlawsandregulationsoftheinterimmeasuresfortheadministrationofpersonalloans,thesemeasuresareformulated.IndividualguaranteearticleIIisanaturalorlegalpersonunitstoprovidesecurityfortheloan,granted
图14
平行四边形的判定
二、课中强化(10分钟训练)
1.如图3,在ABCD中,对角线AC、BD相交于点O,E、F是对角线AC上的两点,当E、F满足下列哪个条件时,四边形DEBF不一定是平行四边形()
A.AE=CFB.DE=BF
C.?
ADE=?
CBFD.?
AED=?
CFB
2.如图4,ABDC,DC=EF=10,DE=CF=8,则图中的平行四边形有_________________,理由分别是_________________、____________________.
图4图5图63.如图5,E、F是平行四边形ABCD对角线BD上的两点,请你添加一个适当的条件:
__________,使四边形AECF是平行四边形.
4.如图6,AD=BC,要使四边形ABCD是平行四边形,还需补充的一个条件是:
______________.
5.如图,在ABCD中,已知M和N分别是边AB、DC的中点,试说明四边形BMDN也是平行四边形.
1、开展一帮一活动,让优秀学生带动后进生,促使他们的转化。
三、课后巩固(30分钟训练)
1.以不在同一直线上的三个点为顶点作平行四边形最多能作()
A.4个B.3个C.2个D.1个2.下面给出了四边形ABCD中?
A、?
B、?
C、?
D的度数之比,其中能判定四边形ABCD是平行四边形的是()
A.1?
2?
3?
4B.2?
2?
3?
3C.2?
3?
3?
2
D.2?
3?
2?
3
第三章圆creditmanagement:
clearconditionsandrequirementsforloanextension.(10)recoveryanddisposal:
1terminayear(including)withintheloan,inadditiontothemonthlyinterestpayment,dueinprincipalrepaymentoptions,youcanalsoselectamatchingservice,equalprincipalrepaymentmethod;2,ClientManagerafterreceivingandreviewingearlyrepaymentoftheapplicationshallbesubmittedtotheheadoftheMarketingDepartmentforreview,processingthroughtheexaminationandapprovalproceduresofrepayment.(11)definedtheoffence.Third,incaseofproblemsduringtheimplementationprocess,pleasecontactHeaddivision.Annex:
qiluBankpersonalloansguaranteedmanagementqiluBankboFebruary1,11keywords:
retailbankingguaranteeloanmanagementofqiluBank'sOfficeissuedonFebruary1,2011Proofreading:
LiuDebaoAnnex:
qiluBankpersonalloansguaranteedManagementchapterIGeneralprovisionsarticletopromotepersonalloansguaranteedbusinessdevelopment,standardizedlendingpractices,accordingtothePeople'sRepublicofChinaoncommercialbanksandtheChinaBankingRegulatoryCommissionandotherlawsandregulationsoftheinterimmeasuresforthe