山东省济南市高新区学年七年级下学期期末考试数学试题Word版含答案.docx
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山东省济南市高新区学年七年级下学期期末考试数学试题Word版含答案
绝密★启用前
2020至2021学年第二学期期末学业水平测试
高新初中数学七年级试题
本试题分第Ⅰ卷(选择题)和第Ⅱ卷(非选择题)两部分.第Ⅰ卷共2页,满分为48分;第Ⅱ卷共5页,满分为102分.本试题共6页,满分为150分.考试时间为120分钟.答卷前,考生务必用0.5毫米黑色墨水签字笔将自己的考点、姓名、准考证号、座号填写在答题卡上和试卷规定的位置上.考试结束后,将本试卷和答题卡一并交回.本考试不允许使用计算器.
第I卷(选择题共48分)
注意事项:
第Ⅰ卷为选择题,每小题选出答案后,用2B铅笔把答题卡上对应题目的答案标号涂黑;如需改动,用橡皮擦干净后,再选涂其他答案标号.答案写在试卷上无效.
一、选择题(本大题共12个小题,每小题4分,共48分.在每小题给出的四个选项中,只有一项是符合题目要求的.)
1.计算
所得结果是( )
A.2021B.
C.﹣
D.﹣2021
2.下面四个图形分别是绿色食品、低碳、节能和节水标志,是轴对称图形的是( )
A.
B.
C.
D.
3.下列4个袋子中,装有除颜色外完全相同的10个小球,任意摸出一个球,摸到红球可能性最大的是( )
A.
B.
C.
D.
4.如图,沿笔直小路DE的一侧栽植两棵小树B,C,小明在A处测得AB=5米,AC=7米,则点A到DE的距离可能为( )
A.4米B.5米
C.6米D.7米
5.在行进路程s、速度v和时间t的相关计算中,若保持行驶的路程不变,则下列说法正确的是( )
A.变量只有速度vB.变量只有时间t
C.速度v和时间t都是变量D.速度v、时间t、路程s都是常量
6.现有两根长度分别3cm和7cm的木棒,若要钉成一个三角形木架,则应选取的第三根木棒长为( )
A.4cmB.7cmC.10cmD.13cm
7.如图,一只电子蚂蚁从正方体的顶点A处沿着表面爬到顶点C处,电子蚂蚁的部分爬行路线在平面展开图中的表示如图的虚线,其中能说明爬行路线最短的是( )
A.
B.
C.
D.
8.等腰三角形的一个内角为50°,它的顶角的度数是( )
A.65°B.80°C.65°或80°D.50°或80°
9.若m,n为常数,等式(x+2)(x﹣1)=x2+mx+n恒成立,则mn的值为( )
A.1B.﹣1C.2D.﹣2
10.如图,将一个长方形纸条折成如图的形状,若已知∠1=140°,则∠2为( )
A.50°B.60°
C.70°D.80°
11.设一个直角三角形的两直角边分别是a,b,斜边是c.若用一把最大刻度是20cm的直尺,可一次直接测得c的长度,则a,b的长可能是( )
A.a=12,b=16B.a=11,b=17C.a=10,b=18D.a=9,b=19
12.如图有两张正方形纸片A和B,图1将B放置在A内部,测得阴影部分面积为2,图2将正方形AB并列放置后构造新正方形,测得阴影部分面积为20,若将3个正方形A和2个正方形B并列放置后构造新正方形如图3,(图2,图3中正方形AB纸片均无重叠部分)则图3阴影部分面积( )
A.22B.24C.42D.44
第Ⅱ卷(非选择题共102分)
注意事项:
1.第II卷必须用0.5毫米黑色签字笔作答,答案必须写在答题卡各题目指定区域内相应的位置,不能写在试卷上;如需改动,先划掉原来的答案,然后再写上新的答案;不能使用涂改液、胶带纸、修正带.不按以上要求作答的答案无效.
2.填空题请直接填写答案,解答题应写出文字说明、证明过程或演算步骤.
二、填空题:
(本大题共6个小题,每小题4分,共24分.)
13.计算(y+2)(y﹣2)的结果等于 .
14.某人连续抛掷一枚质地均匀的硬币3次,结果都是正面朝上,则他第四次抛掷这枚硬币,正面朝上的概率为 .
15.如图,在△ABC中,AD平分∠BAC,∠BAC=80°,
∠B=35°,则∠ADC的度数为 °.
16.某工程队承建30km的管道铺设,工期60天,施工x天后剩余管道ykm,则y与x的关系式为 .
17.如图,在△ABC中,AB的垂直平分线分别交AB,AC于D,E两点,且AC=10,BC=4,则△BCE的周长为 .
第17题图第18题图
18.在直线上依次摆着七个正方形(如图),已知斜放置的三个正方形的面积分别为1,2,3,正放置的四个正方形的面积是S1,S2,S3,S4,则S1+S2﹣S3﹣S4= .
三、解答题:
(本大题共12个小题,共78分.解答应写出文字说明、证明过程或演算步骤.)
19.(本题满分4分)计算:
a3•a2•a+(a2)3.
20.(本题满分4分)计算:
(x﹣3)(x+6).
21.(本题满分4分)如图,在边长为1的小正方形网格中,点A,B,C均落在格点上.
(1)画出△ABC关于直线l的轴对称图形△A1B1C1.
(2)△A1B1C1的形状是.
22.(本题满分5分)填写下列空格:
已知:
如图,CE平分∠ACD,∠AEC=∠ACE.
求证:
AB∥CD.
证明:
∵CE平分∠ACD(已知),
∴∠ACE=∠ ( ).
∵∠AEC=∠ACE(已知),
∴∠AEC=∠ ( ).
∴AB∥CD( ).
23.(本题满分5分)已知:
如图,在△ABC中,BC⊥AC,若AC=8,BC=6,求AB的长.
24.(本题满分6分)如图是一位病人的体温记录图,看图回答下列问题:
(1)自变量是 ,因变量是 ;
(2)护士每隔 小时给病人量一次体温;
(3)这位病人的最高体温是 摄氏度,最低体温是 摄氏度;
(4)他在4月8日12时的体温是 摄氏度.
25.(本题满分6分)先化简,再求值:
(2x+3y)2﹣(2x+y)(2x﹣y),其中x=1,y=﹣1.
26.(本题满分6分)如图,AD是等边△ABC的中线,AE=AD,求∠AED的度数.
27.(本题满分8分)完成下列推理过程:
如图所示,点E在△ABC外部,点D在BC边上,DE交AC于F,若∠1=∠2=∠3,AD=AB.猜想AC与AE之间的数量关系,并说明理由.
答:
ACAE.
解:
∵∠2= ,∠AFE=∠DFC,
∴180°﹣∠2﹣∠AFE=180°﹣∠3﹣∠DFC
∴∠E= .
又∵∠1=∠2,
∴ +∠DAC= +∠DAC.
∴∠BAC=∠DAE().
在△ABC和△ADE中,
∴△ABC≌△ADE().
∴AC=AE.
28.(本题满分8分)一圆盘被平均分成10等份,分别标有1,2,3,4,5,6,7,8,9,10这10个数字,转盘上有指针,转动转盘,当转盘停止,指针指向的数字即为转出的数字,现有两人参与游戏,一人转动转盘另一人猜数,若猜的数与转盘转出的数相符,则猜数的获胜,否则转动转盘的人获胜,猜数的方法从下面三种中选一种:
(1)猜“是奇数”或“是偶数”;
(2)猜“是3的倍数”或“不是3的倍数”;
(3)猜“是大于4的数”或“是不大于4的数”.若你是猜数的游戏者,为了尽可能获胜,应选第几种猜数方法?
并请你用数学知识说明理由.
29.(本题满分10分)如图,△ABC与△ADE是以点A为公共顶点的两个三角形,且AD=AE,AB=AC,∠DAE=∠CAB=90°,且线段BD、CE交于F.
(1)求证:
△AEC≌△ADB.
(2)猜想CE与DB之间的关系,并说明理由.
30.(本题满分12分)“一带一路”让中国和世界更紧密,“中欧铁路”为了安全起见在某段铁路两旁安置了A,D两座可旋转探照灯.假定主道路是平行的,即PQ∥CN,A,B为PQ上两点,AD平分∠CAB交CN于点D,E为AD上一点,连接BE,AF平分∠BAD交BE于点F.
(1)若∠C=20°,则∠EAP= ;
(2)作AG交CD于点G,且满足∠1=
∠ADC,当∠2+
∠GAF=180°时,试说明:
AC∥BE;
(3)在
(1)问的条件下,探照灯A、D照出的光线在铁路所在平面旋转,探照灯射出的光线AC以每秒5度的速度逆时针转动,探照灯D射出的光线DN以每秒15度的速度逆时针转动,DN转至射线DC后立即以相同速度回转,若它们同时开始转动,设转动时间为t秒,当DN回到出发时的位置时同时停止转动,则在转动过程中,当AC与DN互相平行或垂直时,请直接写出此时t的值.
备用图
2020至2021学年第二学期期末学业水平测试
高新初中数学七年级参考答案及评分标准
一、选择题
题号
1
2
3
4
5
6
7
8
9
10
11
12
答案
A
A
D
A
C
B
A
D
A
C
A
C
二、填空题:
(本大题共6个小题,每小题4分,共24分.)
13.y2﹣4.14.
.15.75.16.y=30﹣0.5x17.14.18.﹣2.
三、解答题:
(本大题共12个小题,共78分.解答应写出文字说明、证明过程或演算步骤.)
19.(本题4分)解:
原式=a6+a6·····················································································2分
=2a6·······················································································4分
20.(本题4分)解:
原式=x2+6x﹣3x﹣18·············································································2分
=x2+3x﹣18·················································································4分
21.(本题4分)解:
(1)如图,△A1B1C1为所求;
·······································································································3分
(2)△A1B1C1是等腰直角三角形····················································································4分
22.(本题5分)
DCE;角平分线的定义;DCE;等量代换;内错角相等,两直线平行
23.(本题5分)
解:
∵BC⊥AC
∴∠C=90°··············································································································1分
∵Rt△ABC中,∠C=90°,AC=8,BC=6·····································································3分
∴BC2+AC2=AB2·······································································································4分
AB=10··········································································································5分
24.(本题6分)
解:
(1)时间,体温··········································································································2分
(2)6························································································································3分
(3)39.5,36.8············································································································5分
(4)37.5·····················································································································6分
25.(本题6分)
解:
原式=4x2+12xy+9y2﹣(4x2﹣y2)···················································································2分
=4x2+12xy+9y2﹣4x2+y2=12xy+10y2··················································································4分
当x=1,y=﹣1时,
原式=﹣12+10=﹣2·····································································································6分
26.(本题6分)
解:
∵AD是等边△ABC的中线,
∴∠BAC=60°,AD平分∠BAC·····················································································2分
∴∠CAD
∠BAC=30°································································································3分
∵AD=AE,
∴∠ADE=∠AED·······································································································5分
∴∠AED=75°·············································································································6分
27.(本题8分)每空1分
答:
=
解:
∠3,∠C,∠1,∠2,等式性质,∠E=∠C,AAS
28.(本题8分)
解:
选第2种猜数方法··································································································1分
理由:
P(是奇数)=0.5,P(是偶数)=0.5;
P(是3的倍数)=0.3,P(不是3的倍数)=0.7;
P(是大于4的数)=0.6,P(不是大于4的数)=0.4·········································································7分
∵P(不是3的倍数)最大,
∴选第2种猜数方法,并猜转盘转得的结果不是3的倍数······················································8分
29.(本题10分)
(1)证明:
∵∠BAC=∠DAE,
∴∠BAC+∠CAD=∠DAE+∠CAD,
∴∠BAD=∠CAE·····························································································1分
在△BAD与△CAE中,
···························································································3分
∴△BAD≌△CAE(SAS)···················································································4分
(2)答:
=,⊥············································································································6分
解:
由
(1)知,△BAD≌△CAE,
∴∠ABD=∠ACE,BD=CE··············································································7分
∵∠BAC=90°,
∴∠CBF+∠BCF=∠ABC+∠ACB=90°································································9分
∴∠BFC=90°·······························································································10分
30.(本题12分)
解:
(1)100°···················································································································2分
(2)∵∠1
∠ADC,
∴令∠1
a,则∠ADC=3a························································································3分
∵PQ∥CN,
∴∠ADC=∠BAD=3a
∵AD平分∠BAC,
∴∠CAD=∠ADC=∠BAD=3a················································································4分
∵AF平分∠BAD,
∴∠BAD=2∠EAF.
∴∠EAF=1.5a
∴∠GAF=∠1+∠EAF
∴
∠GAF=3a······································································································5分
∵∠2
∠GAF=180°,
∴∠2+3a=180°.
∴∠2+∠CAD=180°.
∵∠2+∠AEB=180°,
∴∠CAD=∠AEB·································································································6分
∴AC∥BE············································································································7分
(3)t的值为2s或11s或12.5s或17s或21.5s···································································12分