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△ADC中,AB边的高为CD,若=,=,•=0,||=1,||=2,则=( )
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高三下学期数学《》真题及答案
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如图在△ABC中AB=ACD.为边BC上一点以ABBD为邻边作▱ABDE连接ADEC.1求证△ADC
如图四边形ABCD中AC平分∠BAD∠ADC=∠ACB=90E.为AB的中点AC与DE交于点F.1求
从三角形一个顶点向它的对边画______以______和______为端点的线段叫做三角形这边上的高
如图四边形ABCD中∠B.=90°AB∥CDM.为BC边上的一点且AM平分∠BADDM平分∠ADC求
探究如图①在四边形ABCD中∠BAD=∠BCD=90°AB=ADAE⊥CD于点E.若AE=10求四边
在梯形ABCD中AB∥CDCD=2∠ADC=120°cos∠CAD=.1求AC的长2求梯形ABCD的
如图下列判断正确的是
若∠1=∠2,则AD∥BC
若∠1=∠2.则AB∥CD
若∠A.=∠3,则 AD∥BC
若∠3+∠ADC=180°,则AB∥CD
如图已知ABC中AB=ACA.D.⊥AB于点A.交BC边于点E.DC⊥BC于点C.与AD交于点D.1
已知四边形ABCD的一组对边ADBC的延长线交于点E.1如图1若∠ABC=∠ADC=90°求证ED·
如图在△ABC中AB=ACD.为边BC上一点以ABBD为邻边作▱ABDE连接ADEC.1求证△ADC
如图在四边形ABCD中∠B.=∠C.=90°AB>CDAD=AB+CD.1利用尺规作∠ADC的平分线
已知CD是△ABC的边AB上的高若CD=AD=1AB=2AC则BC的长为.
如图AB是⊙O的直径点D在AB的延长线上点C在⊙O上CA=CD∠ACD=120°.1试探究直线CD与
如图在△ABC中AB=ACD.为边BC上一点以ABBD为邻边作▱ABDE连接ADEC.1求证△ADC
如图在△ABC中∠ACB=90°O.为BC边上一点以O.为圆心OB为半径作半圆与AB边和BC边分别交
如图18四边形ABCD中∠B.=90°AB=2CD=8AC⊥CD若则cos∠ADC=______.
如图BE.CF分别是△ABC的边AC.AB上的高且BP=ACCQ=AB.求证1AP=AQ2AP⊥AQ
如图在四边形ABCD中AB=BC对角线BD平分∠ABCP.是BD上一点过点P.作PM⊥ADPN⊥CD
如图在四边形ABCD中∠BAD=∠ADC=90°AB=AD=CD=点P.在四边形ABCD的边上.若点
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如图在△ABC中AB=ACD.为边BC上一点以ABBD为邻边作▱ABDE连接ADEC.1求证△ADC
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Longtimeagotherewasaseed种子andbecausehewasonlyaseednobodynoticedhim.Thusfeelinginferior低等的theseedgavenoimportancetohisexistence. Thenonedayawindpickedhimupandthrewhimonanopenfieldunderthesun.Laterhewasgivenrain. Yearslaterhesawatravelersittingbyhisside.ThankGodforthis.Ireallyneedsomerestheheardthetravelersay. Whatareyoutalkingabout?theseedquicklyasked.Hethoughtthemanwasmakingfunofhim.Nooneeverspoketohimlikethat. Whojustspoke?theshockedmanasked.Itisme.Aseed. Aseed?Themanlookedatthebigtree.Areyoujoking?Youarenotaseed.Youareabigtree! Really? Yes!Whyelsedoyouthinkpeoplecomehere? Whatdotheycomeherefor? Tofeelyourshade树阴!Don'ttellmeyoudidn'tknowyouhadgrownovertime. Amomentpassedbeforethetraveler'swordsbroughthimpride. Theseedthoughtandsmiledforthefirsttimeinhislife.Theyearsoftorture折磨bythesunandtherainfinallyhelpedhimgrowup. Oh!ThatmeansI'mnotalittleseedanymore!Iwasactuallyborntomakepeoplefeelcomfortable.Wow!That'sgreat! 21.Theseeddidn'trealizetheimportanceofhisexistencebecause. A.nobodylookedafterhim B.hewasthrownintotheopenair C.hewassuchasmallseed D.hedidn'tbelieveinhimself 22.Thetravelersatbytheseed'ssideto. A.escapefromtherain B.thankGodforofferinghimatree C.havearestandenjoytheshade D.talkwiththebigtree 23.Howdidtheseedfeelafterhearingthetraveler'swordsatlast? A.Sad. B.Proud. C.Funny. D.Sorry. 24.Wheredoesthepassagemostprobablycomefrom? A.Ahistorybook. B.Asciencebook. C.Astorybook. D.Anovel.
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