2014年人教版八年級(jí)下數(shù)學(xué)期中試題及答案

1、out city created, and care masses life, focus work, in-depth investigation, more out boutique masterpiece, makes we of research results more to into led of decision vision, more to in national some has effect of newspaper shang published, for advance work, and publicity changde play due of role. thi

2、rd, information submitted to be pragmatic. quick and timely. the ancients said: for the time system; statement back for the time being, nothing. therefore, the submission of information to do "four", that is, find the problem faster, editorial writing, send and read faster approval and fee

3、dback to implement quickly. to be true and accurate. true mainly reflect the full picture of events, one is one, two, this is the life of the information. accuracy is primarily qualitative and quantitative questions, quantitative objective of publicqualitative logic. to be reliable and useful. we su

4、bmit information to have access to decision-making, to guide and promote the work and solve practical problems. mixed cum. on the negative information and emergency information, rapid escalation in strict accordance with the procedures, firm, newspaper, newspapers, never late, fail to report, false

5、claim and skimming. investee 2. supervision and insist on, around and protecting their interests to touch the truth, seek practical results. adhere to people-oriented, the most important thing is to realize, safeguard and develop the fundamental interests of the overwhelming majority of the people.

6、we carry out inspection, so must go deep among the masses, go deep into the realities, always pay attention to the people's livelihood, to grasp the public sentiment, and earnestly safeguard the benefit, addressing the masses are most concerned about and reflecting the strongest issues, efforts

7、to solve the problem of decisions implemented and not implemented. one is to stick to principles. right of inspection is one of the most important powers of the office, should not only dare to use, but also with caution. so-called dared to use, is to hold a number of important issues, bold supervisi

8、on over supervision, track inspection, problems are not solved do not pass, the blame does not hold did not miss, dissatisfaction of the masses did not miss, the real right of supervision authority, with the benefits. call with caution, is supervising departments should strengthen the consciousness

9、of authorized strictly according to procedure, preventing the supervision and excessive to prevent adding burden to grass-roots. to this end, the supervision department of the party committee of supervision must be under city and county party committee secretary-general (office). second, we should f

10、ocus on. is the governor, those related to the globalevent, governor the protracted difficult, strong governor during emergency urgent. not having special departments in charge of the general governor, under the normal procedure can do good things not governor, not authorized by county leaders, not

11、the governor. third is to solve the problem. the purpose of supervision, to resolve the problem. to adhere to and further improve the2013-2014學(xué)年度第二學(xué)期八年級(jí)下數(shù)學(xué)期中考試題及答案（人教版）一、選擇題（每小題2分，共12分）1.下列式子中，屬于最簡(jiǎn)二次根式的是（ ）a. b. c. d. 2. 如圖，在矩形abcd中，ad=2ab，點(diǎn)m、n分別在邊ad、bc上，連接bm、dn.若四邊形mbnd是菱形，則等于（ ）a. b. c. d. x k b 1

12、 . c o m2題圖4題圖5題圖3.若代數(shù)式有意義，則實(shí)數(shù)的取值范圍是（ ）a. 1b. 0c. 0d. 0且 14. 如圖，把矩形abcd沿ef翻折，點(diǎn)b恰好落在ad邊的b處，若ae=2，de=6，efb=60°，則矩形abcd的面積是 （ ）a.12 b. 24 c. d. 5. 如圖，正方形abcd的邊長(zhǎng)為4，點(diǎn)e在對(duì)角線(xiàn)bd上，且bae22.5 º，efab，垂足為f，則ef的長(zhǎng)為（ ）a1 b c42 d346.在平行四邊形abcd中，a：b：c：d的值可以是（ ）a.1：2：3：4 b.1：2：2：1 c.1：2：1：2 d.1：1：2：2二、填空題：（每小題

13、3分，共24分）10題圖7.計(jì)算：= .8.若在實(shí)數(shù)范圍內(nèi)有意義，則的取值范圍是 . 9.若實(shí)數(shù)、滿(mǎn)足，則= . 10.如圖，abcd與dcfe的周長(zhǎng)相等，且bad=60°，f=110°，則dae的度數(shù)書(shū)為 11.如圖，在直角坐標(biāo)系中，已知點(diǎn)a（3，0）、b（0，4），對(duì)oab連續(xù)作旋轉(zhuǎn)變換，依次得到1、2、3、4，則2013的直角頂點(diǎn)的坐標(biāo)為 12.如圖，abcd是對(duì)角線(xiàn)互相垂直的四邊形，且ob=od,請(qǐng)你添加一個(gè)適當(dāng)?shù)臈l件 _,使abcd成為菱形.（只需添加一個(gè)即可）13 .如圖，將菱形紙片abcd折疊，使點(diǎn)a恰好落在菱形的對(duì)稱(chēng)中心o處，折痕為ef.若菱形abcd的邊長(zhǎng)

14、為2cm，a=120°，則ef= . w w w .x k b 1.c o14.如圖，矩形abcd中，ab=3，bc=4，點(diǎn)e是bc邊上一點(diǎn)，連接ae，把b沿ae折疊，使點(diǎn)b落在點(diǎn)b處，當(dāng)ceb為直角三角形時(shí)，be的長(zhǎng)為_(kāi).13題圖12題圖11題圖ecdbab 三、解答題（每小題5分，共20分）15.計(jì)算：14題圖16. 如圖8，四邊形abcd是菱形，對(duì)角線(xiàn)ac與bd相交于o,ab=5,ao=4,求bd的長(zhǎng).新課 標(biāo) 第 一 網(wǎng)16題圖17.先化簡(jiǎn)，后計(jì)算：，其中，.18. 如圖，在平行四邊形abcd中，對(duì)角線(xiàn)ac,bd交于點(diǎn)o,經(jīng)過(guò)點(diǎn)o的直線(xiàn)交ab于e，交cd于f.求證：oe=of

15、.18題圖四、解答題（每小題7分，共28分）19. 在矩形abcd中，將點(diǎn)a翻折到對(duì)角線(xiàn)bd上的點(diǎn)m處，折痕be交ad于點(diǎn)e將點(diǎn)c翻折到對(duì)角線(xiàn)bd上的點(diǎn)n處，折痕df交bc于點(diǎn)f（1）求證：四邊形bfde為平行四邊形；新課 標(biāo) 第 一 網(wǎng)（2）若四邊形bfde為菱形，且ab2，求bc的長(zhǎng)19題圖abcdnmp20. 如圖，在四邊形abcd中，ab=bc，對(duì)角線(xiàn)bd平分 Ðabc，p是bd上一點(diǎn)，過(guò)點(diǎn)p作pmad，pncd，垂 足分別為m、n。 (1) 求證：Ðadb=Ðcdb； (2) 若Ðadc=90°，求證：四邊形mpnd是正方形。20題圖

16、21.如圖，在abcd中，f是ad的中點(diǎn)，延長(zhǎng)bc到點(diǎn)e，使ce=bc，連結(jié)de，cf。（1）求證：四邊形cedf是平行四邊形；（2）若ab=4，ad=6，b=60°，求de的長(zhǎng)。x21題圖22.如圖，四邊形abcd是平行四邊形，de平分adc交ab于點(diǎn)e，bf平分abc，交cd于點(diǎn)f（1）求證：de=bf；（2）連接ef，寫(xiě)出圖中所有的全等三角形（不要求證明）22題圖五、解答題（每小題8分，共16分）23. 如圖，在abc中，acb=90°，ba，點(diǎn)d為邊ab的中點(diǎn)，debc交ac于點(diǎn)e，cfab交de的延長(zhǎng)線(xiàn)于點(diǎn)f（1）求證：de=ef；w w w .x k b 1.

17、c o m（2）連結(jié)cd，過(guò)點(diǎn)d作dc的垂線(xiàn)交cf的延長(zhǎng)線(xiàn)于點(diǎn)g，求證：b=a+dgc23題圖24. 2013如圖，在矩形abcd中，e、f分別是邊ab、cd上的點(diǎn)，aecf，連接ef、bf，ef與對(duì)角線(xiàn)ac交于點(diǎn)o，且bebf，bef2bac。 （1）求證；oeof； （2）若bc，求ab的長(zhǎng)。24題圖新- 課 -標(biāo)- 第 -一- 網(wǎng)六解答題：（每小題10分，共20分）25. 如圖1，在oab中，oab=90°，aob=30°，ob=8以ob為邊，在oab外作等邊obc，d是ob的中點(diǎn)，連接ad并延長(zhǎng)交oc于e（1）求證：四邊形abce是平行四邊形；（2）如圖2，將圖1中

18、的四邊形abco折疊，使點(diǎn)c與點(diǎn)a重合，折痕為fg，求og的長(zhǎng)25題圖新|課 |標(biāo) |第 |一| 網(wǎng)26. 如圖，在等邊三角形abc中，bc=6cm. 射線(xiàn)ag/bc，點(diǎn)e從點(diǎn)a出發(fā)沿射線(xiàn)ag以1cm/s的速度運(yùn)動(dòng)，同時(shí)點(diǎn)f從點(diǎn)b出發(fā)沿射線(xiàn)bc以2cm/s的速度運(yùn)動(dòng)，設(shè)運(yùn)動(dòng)時(shí)間為t(s).（1）連接ef，當(dāng)ef經(jīng)過(guò)ac邊的中點(diǎn)d時(shí)，求證：adecdf；（2）填空：當(dāng)t為_(kāi)s時(shí)，四邊形acfe是菱形；當(dāng)t為_(kāi)s時(shí)，以a、f、c、e為頂點(diǎn)的四邊形是直角梯形.26題圖參考答案1.b；2.c；3.d；4.d；5.c；6.c；7.-7；8. ；9. ；10.25°；11. （8052，0）；1

19、2. oa=oc或ad=bc或adbc或ab=bc；13. ；14. 或3；15. ；16. 解：四邊形abcd是菱形，對(duì)角線(xiàn)ac與bd相交于o，acbd，do=bo，ab=5，ao=4，bo=3，bd=2bo=2×3=6w w w .x k b 1.c o17. ：原式 當(dāng)，時(shí)，原式的值為。18. 證明：四邊形abcd是平行四邊形，oa=oc,abcd oae=ocf aoe=cof oaeocf（asa） oe=of 19. （1）證明：四邊形abcd是矩形，a=c=90°，ab=cd，abcd，abd=cdb，在矩形abcd中，將點(diǎn)a翻折到對(duì)角線(xiàn)bd上的點(diǎn)m處，折痕b

20、e交ad于點(diǎn)e將點(diǎn)c翻折到對(duì)角線(xiàn)bd上的點(diǎn)n處，abe=ebd=abd，cdf=cdb，abe=cdf，在abe和cdf中abecdf（asa），ae=cf，四邊形abcd是矩形，ad=bc，adbc，http:/w ww.xk b1. comde=bf，debf，四邊形bfde為平行四邊形；（2）解：四邊形bfde為為菱形，be=ed，ebd=fbd=abe，四邊形abcd是矩形，ad=bc，abc=90°，abe=30°，a=90°，ab=2，ae=，be=2ae=，bc=ad=ae+ed=ae+be=+=220. (1) bd平分Ðabc，

21、8;abd=Ðcbd。又ba=bc，bd=bd， abd cbd。Ðadb=Ðcdb。 (4分) (2) pmad，pncd，Ðpmd=Ðpnd=90°。 又Ðadc=90°，四邊形mpnd是矩形。 Ðadb=Ðcdb，pmad，pncd，pm=pn。 四邊形mpnd是正方形。21.（1）略（2）22. 證明：（1）四邊形abcd是平行四邊形，dcab，cde=aed，de平分adc，ade=cde，新課 標(biāo) 第 一 網(wǎng)ade=aed，ae=ad，同理cf=cb，又ad=cb，ab=cd，ae=

22、cf，df=be，四邊形debf是平行四邊形，de=bf，（2）adecbf，dfebef23.解答：證明：（1）debc，cfab，四邊形dbcf為平行四邊形，df=bc，d為邊ab的中點(diǎn)，debc，de=bc，ef=dfde=bccb=cb，de=ef；（2）四邊形dbcf為平行四邊形，dbcf，adg=g，acb=90°，d為邊ab的中點(diǎn)，cd=db=ad，b=dcb，a=dca，dgdc，dca+1=90°，x|k | b| 1 . c|o |mdcb+dca=90°，1=dcb=b，a+adg=1，a+g=b24. （1）證明：四邊形abcd是矩形 ab

23、cd，oaeocf，oeaofc aecf aeocfo（asa） oeof （2）連接bo oeof，bebf boef且ebofbo bof900 四邊形abcd是矩形 bcf900 又bef2bac，befbaceoa baceoa aeoe aecf，oeof ofcf 又bfbf bofbcf（hl） obfcbf cbffboobe abc900 obe300 beo600 bac300ac=2bc=，ab=25.（1）證明：rtoab中，d為ob的中點(diǎn)，do=da，dao=doa=30°，eoa=90°，aeo=60°，又obc為等邊三角形，bco=

24、aeo=60°，xk b1.c ombcae，bao=coa=90°，coab，四邊形abce是平行四邊形；（2）解：設(shè)og=x，由折疊可得：ag=gc=8x，在rtabo中，oab=90°，aob=30°，bo=8，ao=，在rtoag中，og2+oa2=ag2，x2+（4）2=（8x）2，解得：x=1，og=126.（1） 證明： 是邊的中點(diǎn) 又adecdf（2）當(dāng)四邊形是菱形時(shí)， 由題意可知：， 若四邊形是直角梯形，此時(shí) 過(guò)作于m，可以得到， 即， 此時(shí)，重合，不符合題意，舍去。 若四邊形若四邊形是直角梯形，此時(shí)， abc是等邊三角形，f是bc中點(diǎn)

25、， ，得到 經(jīng)檢驗(yàn)，符合題意。x k b 1 . c o m 新課 標(biāo)第 一 網(wǎng) 整個(gè)外腳手架工程涉及到搭設(shè)、維護(hù)及拆除三個(gè)階段，根據(jù)各個(gè)階段的不同工作內(nèi)容，勞動(dòng)力的需用情況不同。本工程主體施工進(jìn)度要求較快，外腳手架工作量較大，需投入較多勞動(dòng)力，外腳手架將根據(jù)現(xiàn)場(chǎng)分棟搭設(shè)。外腳手架維護(hù)階段主要是配合外裝單位進(jìn)行施工，因此需用勞動(dòng)力較少feelings survey, by looking up public sentiments to find problems. problems will increase its special supervision, set up accounts,

26、hold on to it. we should conscientiously implement the leading contracting matters, secured, had an answer to everything, then settles rate of 100%. have an impact on some of the outstanding issues, supervision departments and information components together, play the supervisory role of the news me

27、dia to promote problem solving. investee 3. insist on a daily run, around the practice of truth catching efficiency, focus specification. to give full play to the party office around connecting, coordinating internal and external features, contact, rally at all levels, to motivate every aspect, adhe

28、re to the truth, strengthening standardized management to achieve coherent, efficient and effective functioning of the daily work of the party committee. is processing messages should strive to streamline, standardize and quality. streamlining is to control the number of messages, compress messages,

29、 reducing procedures, improve message handling efficiency. specifications, is to strictly enforce the ban issued by the communist party authorities in document handling regulations and provincial and municipal regulations, conscientiously strengthen and improve communications management to ensure th

30、at party documents orderly. high quality, is to improve the quality of message processing, it is necessary to accurately implementing the intention of the party committee, clearance, good communications, policy program closed, ensuring that there is no error. second meeting scheduled to ensure thoro

31、ugh, safe and efficient. any arrangements for the meetings and events, carefully arranged, item-by-item interface implemented, sure. to vigorously streamline meetings, activities, number of pressure reduction, scale to ensure that leadership emerged from the general conference and entertainment services, focus on big things, matters. third, reception services should lay stress on humane, personal, cultural and human. reception a