最新13.4(3)平行线的判定PPT课件.ppt

《最新13.4(3)平行线的判定PPT课件.ppt》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。

1、复习：1、判定两直线平行常用的三种方法：A同位角相等，两直线平行；M内错角相等，两直线平行；BF32同旁内角互补，两直线平行；12、如图，CDE（1）若∠1=∠2，那么_B_F__//___C_D（内错角相等，两直线平行）（2）若∠1=∠M，那么__A_M_//__C_D_（内错角相等，两直线平行）（3）若∠1=∠C，那么_A__C_//___D_M_（同位角相等，两直线平行）（4）若∠1+∠2=180°，那么__B_F_//__C_D_（同旁内角互补，两直线平行）例题例1如图，已知BE平分∠ABC，∠1

2、=∠3，DE与BC平行吗？为什么？ADE312BC拓展：如图，已知∠ABC=∠ADC，BF和DE分别平分∠ABC和∠ADC，∠1=∠2.问：BF和DE平行吗？为什么？AE23D1CBF1宾语从句和表语从句•AwhatBthat•1.HetelephonedMary_____hewantedtoseeher.•2.Thisis____Iwanttosayandthatisall____Iwanttodo.•3.Thecoffeewehadtodaywasdifferentfrom____wehadyeste

3、rday.•4.MadameCuriediscovered____shecalledradium.•Ifwhether•1.Iwanttoknow____shehasgoneshopping.•2.Wewondered____thatmanwasaspyornot.•3.Itdependson___wewillbereadyintime.•4.Idon’tknow____hewon’tcometotheoffice.•5._____hecomes,I’lltellhimatonce.•6.Almostal

4、lpeopleenjoysports,____boysorgirls,menorwomen.•Whowhoever•1.Wehaven’tdecided_____willgotothesalesdepartment.•2.Teachersseemtolike____workshardatschool.•1.Wouldyoumindtellingme_____languageyourfriendspeaks?•AwhichBwhatChowDthat•2.ThenMrSmithtoldme___hewasd

5、oingwasveryimportant.•AthatBwhyCwhatthatDwhywhat•3.Someofthescientiststhink____thebooksaidwasright.•AwhatwhatBthatwhat•CwhatthatDthatthat•4.Thedifficultywenowmeetwithis____wecanpersuadehimtotellthetruth.•AwhetherBthatCwhatDwhy•5.Determinationisakindofbasi

6、cqualityandthisis____ittakestojobswell.•AwhatBthatCwhichDwhy•6.Amoderncityhasbeensetupin___wasawastelandtenyearsago.•AwhatBwhichCthatDwhere•7.Ithinkfatherwouldliketoknow____I’vebeenuptosofar,soIdecidetosendhimaquicknote.•AwhichBwhyCwhatChow•8.Iwassurprise

7、dbyherwords,whichmademerecognize_____sillymistakesIhadmade.•AwhatBthatChowDwhich•9.Themotherdidn’tknow____toblameforthebrokenglassasithappenedwhileshewasout.•AwhoBwhenChowDwhat•10.Pleasetellme___youwantyourcoffee,blackorwhite?•AwhenBwhatChowDwhich•11.When

8、Itrytounderstand____thatpreventschildrenfromgettingfat,itseemstomethattherearetworeasons.•AwhyitisBwhatitis•CwhyisitDwhatisit•12.Ibelieve_____you’vedoneyourbestand____thingswillimprove.•Athat;/B/;/Cwhat;thatD/;that•