人教版数学八年级下册《期中考试卷》含答案

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ᡂஹ⌱⚪ᜧ⚪ᐳ8⚪⚪ᨵ⌱⚗ᔠ⚪⌕,⚪4ᑖᑖ32ᑖ.1.x/rᙠᦪᑁᨵ"#ᑣXḄ&')A.x>2B.x<2C.x>2D.x<22.(ᑡ*᪷,-ᨬ/*᪷,0c-QD-.A.B.^83.(ᑡ1234Ḅ0A.+#=#>B.36-6=3C.VSxV7=76D.V454-75=734.᝞AᙠRfABC-,NACB=90°,AB=10,CD0ABBC-;ᑣCDḄP0ூ௃CCADB5A.20B.10C.5D.-25.DE,FE,3GEHᐹᨵḄឋK0A.ᩩ9:;MᑖN9:B.9:;=OC.9:;<=MᑖD.9:;<=ᚖ?

16.TUxஹy0ᦪXY+y26^+9=0,ᑣ2*3Ḅ'0A.6B.-6C.-ID.07.᝞ATU3GEAḄ☢ij25,3GECḄ☢ij169,mn3GEBḄ☢i08.TUp|a|=2,=3,s|a+b|=a+b,ᑣa-bḄ'jA.1ᡈ5B.1ᡈ-5C.-1ᡈ5D.-1ᡈ-5ஹvw⚪ᜧ⚪ᐳ6⚪⚪3ᑖᑖ18ᑖ.9.12p᝞24.10.x*yzFEᔜB-|ᡠ~ᑮḄXBE011.᝞AজAB//CDঝAB=CDঞBC//ADটBC=ADXᩩ-⌱XBEABCD0MXBEḄ⌱ᨵᑏD12.᝞BPᑖj5cm8cmḄDE3GEḄ☢i=O,mn3GEḄBPj<13.(ᑡᔜ,:¡¢Ḅ£¤ᵨ¦§ᯠᦪnn>lḄO,⊤ᩭ14.᝞ATUDEABCD°Ḽ?;BDᢚ³|C´ᙠ஺ᜐ,B஺·AD¸E,AD=4,AB=2,ᑣDEPj

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11,316.᝞AXBEABCD0ᙽ₝Æ,Ç~XBPAB=3m,BC=4m,DC=l2m,AD=\3m,ZB=90°,ᙽ₝Æ☢i.17.ᐜᓄ/Ê'^--,ᐸ-x=G+l,y=6—1•18.᝞Aᙠ3GEABCDḄ᜜ÐÑOB4ADE.NAEBḄÒᦪ.19.▅Ô(☢Õ⚪:τÖ6T1T77T□]3ᔆ”16ᨵ+06+@Ý_a]_]xG@a+64+যàṹ1p17777T--------------1(2)â“j3᦮ᦪå+1+4

3111312:------1--------1-------F…H----------1-----------1+V2¿+GV3+V4V98+V99V99+V10020.᝞Aᡠ,00DEABCDḄ9:;Ḅ·|ÑDE஻AC,CE//BD,DEஹCE=·¸|E.çp1XBEOCED0FE.2yzOE,AD=5,CD=3,FEOCEDḄ☢i.21.᝞A,ABCD0?:éE,CD=12cm,AB=15cm,|PB|ëì,°BABᔣ|AÖlcm/sḄïÒðñ,|QD|ëì°DCBᔣ|CÖ2cm/sḄïÒðñ᝞PஹQᑖBஹDóå¡,PஹQᨵ|ᑮôõ|åöñ÷ø,ùðñåújt.Õtjü'åXBEPQCB0MXBEý22.᝞AᙠDABC-A3=AC,AO_L5C,ᚖÿ
஺,ANDABC᜜NC4MḄᑖCELAN,ᚖ
E.1!AOCE#!2%□ABC'()ᩩ+,!ADCE-./0!?2345.23.᝞8ᙠ/0!ABCD:,EAB;-
,FAD=>;-
?DF=BE

4(1)CE=CFA(2)B
GᙠAD;?NGCE=45°,ᑣGE=BE+GDᡂEᔩ?()G

5HᫀJK᪆-ஹ⌱O⚪Qᜧ⚪ᐳ8.T⚪U.T⚪Vᨵ-.⌱⚗Yᔠ⚪[⌕,UT⚪4ᑖ'ᑖ32ᑖ.1.B]ᙠ^ᦪaᑁᨵcdᑣxḄefaA.x>2B.x<2C.x>2D.x<2ூHᫀ௃AூK᪆௃ூᑖ᪆௃ij᪷lᨵcd,mn0ᦪopᦪ,ᓽx-2>0,KrslxḄefa.ூtK௃/vᙠ^ᦪaᑁᨵcdx-2>0,Kwx>2.ᦑHᫀ⌱A.ூ
y௃Q⚪ὃ{|ij᪷lᨵcdḄᩩ+,K⚪Ḅᐵ~Ḅij᪷lᨵcdḄᩩ+.2.ᑡij᪷l:ᨬij᪷lA.^/4B.y/sC.D.vnூHᫀ௃DூK᪆௃ூᑖ᪆௃᪷ij᪷lḄឋJᨬij᪷lḄdᓄᓽ.ூtK௃A.6=2,ᦑrᨬij᪷lAB.▭=2ᦑrᨬij᪷lAC.=|ᦑrᨬij᪷lAD.vnᨬij᪷lAᦑ⌱D.

6ூ
y௃Q⚪ὃ{|ᨬij᪷lḄ᝞ij᪷lḄmnl:rᑖ2?rᨵnḄ0Ḅl᪵Ḅij᪷lᨬij᪷l.3.ᑡ/¡ḄA.0+G=&B.372-72=3C.V14XV7=7V2D•©ᓝ«=6ூHᫀ௃CூK᪆௃ூᑖ᪆௃᪷ᔠ2®⚗¯ᑣஹij᪷lḄ°±²◀´¯ᑣ--µᔜ⌱⚗ᓽwᑮHᫀAூtK௃KAஹ0+¸=0+bᦑ⌱⚗A┯»ABஹ3c-⊈=20ᦑ⌱⚗B┯»ACஹ==7¾ᦑC⌱⚗/¡ADஹ©=®=3,ᦑD⌱⚗┯»Aᦑ⌱CAூ
y௃Q⚪À⌕ὃ{|ᔠ2®⚗¯ᑣஹij᪷lḄ°±²◀´¯ᑣ,®⚗Ḅdஹij᪷lḄ´¯ᑣK⚪Ḅᐵ~A4.᝞8ᙠRfABC:,NACB=90°,AB=10,CDAB;Ḅ:ᑣCDḄ>ூ௃5A.20B.10C.5D.-2ூHᫀ௃CூK᪆௃ᵫÅÆ!ḄឋÇÈ;Ḅ:sÉÈḄ-Êᓽ4CDḄ>•ᙠRbABC:,NACB=90°,AB=10,CDAB;Ḅ:...CD=AAB=5.ᦑ⌱C5.#!Ë!/0!ᐹᨵḄឋ

7A.U-ᩩÍᑖ-ÎÍB.ÍÏsC.ÍÐÏᑖD.ÍÐÏᚖÅூHᫀ௃CூK᪆௃ூᑖ᪆௃#!Ë!/0!ᱯÒḄÓ!ÔÓ!ᐹᨵḄឋÕ#!Ë!/0!ᐹᨵḄឋ.ூtK௃Aஹ#!ḄÍr-ᑖ-ÎÍᦑA┯»ABஹ#!ஹ/0!ḄÍÏsÔË!ḄÍrÏsᦑB┯»ACஹ#!Ë!/0!ḄÍᙳÐÏᑖᦑC/¡ADஹË!ḄÍÐÏᚖÅÔ#!ḄÍrÐÏᚖÅᦑD┯».ᦑ⌱C.ூ
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#!Ú/0!ḄÍÏsË!Ú/0!ḄÍÐÏᚖÅÛᳮK×⚪Ḅᐵ~.6.ÝÇxஹy^ᦪ-2x+3+y2—6y+9=0,ᑣ2x-yḄf()A.6B.-6C.-1D.0ூHᫀ௃BூK᪆௃ூᑖ᪆௃ᐜᓄál,â᪷ã.opᦪäÚå,ᑣU-.opᦪå4xÚyḄf,ᨬæçᐭçᦪlᓽK.ூtK௃éáslᓄwj2x+3+(y-3)2=0,᪷⚪cw2x+3=0,y-3=0,3Kwx———,_y=3,2ᑣál=2*(-|)-3=-6,

8ᦑ⌱B.ூ
y௃Q⚪ὃ{çᦪlf,K⚪Ḅᐵ~᪷opᦪḄឋᑡl4ëÇᦪḄf.7.᝞8ÝÇ/0!AḄ☢í25,/0!CḄ☢í169,î)/0!BḄ☢í()B.169C.25D.194ூHᫀ௃AூK᪆௃ூᑖ᪆௃ïᔠðñᳮÚ/0!Ḅ☢íòl,wóCᡠç⊤Ḅ/0!Ḅ☢ísÉᐸØ÷./0!Ḅ☢íø.ூtK௃K᪷⚪cÇ/0!ḄC☢í169,/0!AḄ☢í25,ᑣóBᡠç⊤Ḅ/0!Ḅ☢í=169-25=144.ᦑ⌱A.ூ
y௃Q⚪ὃ{|ðñᳮK⚪Ḅᐵ~ùÅÆ!Ḅ÷ᩩÅ>Ḅ/0!Ḅ☢íÚsÉùÈ>Ḅ/0!Ḅ☢í.8.ÝÇ|a|=2,=3,?|a+b|=a+b,ú!]a-bḄf()A.1ᡈ5B.1ᡈ-5C.-1ᡈ5D.-1ᡈ-5ூHᫀ௃DூK᪆௃ூᑖ᪆௃ᐜ᪷þÍfÚᦪ0᪷Ḅd4aஹbḄf,âçᐭᑮa-bᓽ.ூtK௃V|a|=2,=3,a=±2,b=±3,*.*|a+b|=a+b,a+beO,a=2,b=3ᡈa=-2,b=3,.*.a-b=2-3=-lᡈa-b=-2-3=-5.

9ᦑ⌱D.ூ
y௃Q⚪ὃ{|þÍfÚᦪ0᪷Ḅdù¾ᑖ®ÿḄᦪ,aஹbḄ⚪Ḅᐵ.ஹ⚪ᜧ⚪ᐳ6⚪⚪3ᑖᑖ18ᑖ.9.V18-2/_.ூᫀ௃272ூ᪆௃ᐜᔜ᪷"ᓄ$ᨬ&'(᪷",)ᔠ+,-⚗ᓽ0.1"=32-J5=272.ᦑᫀ$25.10.6(789:ᔜ;<=ᡠ?ᑮḄA;:.ூᫀ௃B:ூ᪆௃VE.F.GஹHᑖDABஹADஹCDஹBCḄ<=,EF//BD,FG//AC,HG//BD,EH//AC,EF஻HGEH஻FG,A;:EFGHGHA;:I♦••A;:ABCD9:IAACIBD,EF஻BD,EH஻AC,AEFIEH,

10IZFEH=90°,.•.GHA;:EFGHB:Iᦑᫀ$B:.11.᝞LIMজAB//CDঝAB=CDঞBC//ADটBC=ADRASᩩU

11(n>l)Ḅ"⊤ᩭூᫀ௃ஹ஻+'aV5+w¢(஻¤n+2ூ᪆௃ூᑖ᪆௃ᑖ᪆0?=(3+13+2Iᑣ¬ᵨᯠᦪn(nl)Ḅ"⊤ᩭஹV஻+——=(»1)©1(”«n+2ூo௃ᵫᑖ᪆0°IḄᵨᯠᦪn(n2l)Ḅ"⊤ᩭ=5ᵲ+!1ᦑᫀ$./nd--=---5----+1—±²1Vn+2ூ=q௃⚪r⌕ὃu'(᪷"I³⚪<Ḅ⚪Ḅᐵ|Iᔜ",´µ¶·?ᑮa¸ឋIᑏᵨn⊤Ḅ"ᓽ0.14.᝞LIº°B:ABCD»Ḽ½lBDᢚ¿IZ=CÀᙠ஺ᜐ,BCIÄADE,AD=4,AB=2,ᑣDEḄ~$ூᫀ௃2.5ூ᪆௃ூᑖ᪆௃ᐜ᪷pᢚ¿ḄឋÅ?ZC-BD=ZCBD,)ᑭᵨB:ḄឋÅ?AD஻BC,ᑣZEDB=ZCBD,ᡠNEDB=NCBD,᪷pῪÈk:Ḅᑨeeᳮ?EB=ED,ÉAE=xIᑣED=AD-AE=4-x,BE=4-x,ᙠRtAABE

12A;:ABCD$B:I.AD஻BC,ZEDB=ZCBD,ZEDB=ZC,BD,IEB=ED,ÉAE=x,ᑣED=AD-AE=4-x,BE=4-x,ᙠRMABE

13=3-25/3•ூ)*௃+⚪ὃ.Ḅ012᪷4Ḅ56,728,9:;,<=>?᪷,@᦮ᦪᢣᦪḄA<,BCDEFG0⚪0ᐵI.16.᝞KLMNABCD0Oᙽ₝R,STLMUAB=3m,BC=4m,DC=12m,AD=13m,NB=90஺,Z[ᙽ₝RḄ☢].ூ^ᫀ௃[ᙽ₝RḄ☢]0365ூ᪆௃a⚪ᑖ᪆cdeAC,ᵫNB=90o,AB=3cm,BC=4cmFAC=5cmlᵫACஹADஹCDḄUᑨpqAACD0rstsN,᪷uvtsNḄ☢]Zq₝RḄ☢].a⚪᪆cRtAABCy,AB=3m,BC=4m,/B=90஺ᵫz{|ᳮTAB2+BC2=AC2AC=5mᙠAADCyAC=5m,DC=12m,AD=13mAC2+DC2=169,AD?=169.\AC2+DC2=AD2ZACD=90°LMNḄ☢]=SRtAABC+SRlAADC^-ABxBC+-ACxDC22=—x3x4+—*5x1222=36(m2)22'17.ᐜᓄZ;'---------ᓛᐸy=&+1,?=6—1.

14ூ^ᫀ௃Oᚆ1B.x+y3ூ᪆௃ூᑖ᪆௃ᐜ᪷uᐰ>?4:8O4ᓄḄ4ᑖᔠ,◀ᡂ¢D᎔ᦪᙠ¤ᑖ,x=J5+l,y=6—1¥ᐭᓄḄ§¨ᓽTᑮ^ᫀlஹIª:ߟ-X2y…c"7ஹx-y(®,®x-y(x+y)(x-y)x+y¯x=G+l,y=6—1°®_ᔣ1/1_2³4="µ¶+1+!tO·O;ூ)*௃+⚪¹⌕ὃ.»ᑖ4ḄᓄZ;,BC>?4¼ᐰ>?40⚪ḄᐵI;18.᝞Kᙠ½?NABCDḄ᜜¿ÀÁM4ADE.ZNAEBḄÂᦪ.ூ^ᫀ௃150.ூ᪆௃ூᑖ᪆௃᪷uLMNABCDý?NZXADEÃÁMtsNTᑮAB=AD=AE,NBAD=90஺/DAE=60஺ᓽTᑮZBAE=150°,᪷uAB=AETÄIj/AEB=/ABEᓽZlூ௃•cLMNABCDý?N,AADEÃÁMtsN

15AB=AD=AE,ZBAD=90°,ZDAE=60°,JZBAE=ZBAD+ZDAE=150°,XVAB=AE,.\ZAEB=ZABE,ZAEB=1(180°-150°)=15°=15°(tsNḄᑁsÇ).ூ)*௃+⚪¹⌕ὃ.»½?NḄឋÉஹÁMtsNḄឋÉஹtsNḄᑁsÇ|ᳮBC½?N¼ÁMtsNḄឋÉ0⚪ḄᐵI.19.▅ËÌ☢Í⚪:1MgXÑ+ªÒ111x!-ÑqRᕒ⊈—6+ẠÖযª_1x74-73_"+6O"+@Gg1Z:1Ù7T--------------:2¯”ý᦮ᦪ°1-----__Ü=l/7+1+ஹḕ]1]]]ব"c1+72+V2+V3+V3+V4++V98+V99+V99+V100ூ^ᫀ௃1V7-V6;2lব9.ூ᪆௃ூᑖ᪆௃

16(1)à᯿⚪âᡠäḄᑖåᨵᳮᓄḄ?ç?4ᡠDOù12᪷4Ḅᨵᳮᓄú40ûᔠ>?4Ḅᱯ)Ḅ4.ᓽO⚗ûÇ9:;þÿ
⚗.20.᝞ᡠ,0ABCDḄḄDE//AC,CE//BD,DEஹCEE.(1)"#OCED$.(2)%&OE,'AD=5,CD=3,$OCEDḄ☢).ூᑖ᪆௃(1)✌ᐜᵫDE//OC,CE//OD,./"#CODE01"#,3ᵫ"#ABCD᪷5Ḅឋ7᧕/OC=OD,ᓽ.ᑨ;"#CODE$

17(2)="#AOED01"#,/ᑮOE=AD,?᪷5$OCEDḄ☢)=COxOEᓽ.@AB⚪.2ூE@௃@(1)=GDE//OC,CE//OD,"#OCED01"#.•.."#ABCD.\OC=OD."#OCED$G(2)᝞%&0E.ᙠ$OCEDJ,OECD,.,.OE//AD.3,/DE//AC,"#AOED01"#/.OE=AD=5.ூL௃M⚪ὃOPḄឋ7ஹ$Ḅᑨ;Qឋ7ஹRS;ᳮUVW,XYZ[$Ḅᑨ;\]@⚪Ḅᐵ_,`aḄbᑖᡂ☢)UḄ4ef,gJὃhὃ⚪i.21.᝞,ABCDjk,CD=12cm,AB=15cm,PlBmn,oBA#ᔣAqlcm/sḄrstuQlDmnoDC#ᔣCq2cm/sḄrstu᝞vPஹQᑖwlBஹDxyz,PஹQᨵᑮ|}x~u,tuxt.Btx"#PQCB01"#Dஹ___________Q_______CApBூᫀ௃t=4sx"#PQCB01"#.ூ@᪆௃ூᑖ᪆௃'"#PQCB01"#,ᑣQC=PB,ᓽDC-2t=t,ytᓽ..ூE@௃G"#PQCB01"#

18QC=PB,ᓽDC-2t=t,A12-2t=t,@/t=4G/.t=4sx"#PQCB01"#.ூL௃⚪⌕ὃOP01"#Ḅឋ7᪷5ឋ7/ᑮ\DC-2t=t@M⚪Ḅᐵ_.22.᝞ᙠ43஺JAJB=AC,A஺_LBC,ᚖ஺,ANA3C᜜NC4MḄ0ᑖ6^4"ᚖ£.1"#AQCEG2□A3cᩩx"#ADCEe\?¡¢y=.ூᫀ௃1=£@᪆G243஺NB4C=90°x"#ADCEe\=£@᪆.ூ@᪆௃ூᑖ᪆௃1ᐜ᪷5UῪfḄfᔠ./NBAD=NC4O,?᪷50ᑖḄ;¦.//MAE=ZCAE,l§./ZDAE=90°,ᯠ©᪷5ᚖjḄ;¦./ZADC=ZAEC=90°,ᨬ©᪷5Ḅᑨ;ᓽ./;2ᐜ᪷5UῪjfḄឋ7./NACB=NB=45°,?᪷5jfḄឋ7./ZCAD=ZACD=45°,ᯠ©᪷5UῪfḄ;¦./CO=AO,ᨬ©᪷5\Ḅᑨ;ᓽ./.ூE@௃1•.•ᙠDABCJAB=AC,AD±BC,ABAD=ACADABACUῪfḄfᔠ2•••ANABC᜜ZCAMḄ0ᑖZMAE=ZCAE=-ZCAM,2

19ZDAE=ACAD+ZCAE=-ZBAC+-ZCAM=xl80°=90°,2223AD±BC,CE±AN,5.ZADC=ZAEC=90°,"#AOCEG(2)ABCNBAC=90஺x"#ADCEe\=᝞º•/AB=AC,ZBAC=90°,ZACB=NB=45°,ADIBC,5.ZCAD=ZACD=45°,CD=AD,•.•"#ADCEAOCE\ᦑZBAC=90°x"#ADCEe\.ூL௃⚪ὃOP\QḄᑨ;ஹUῪfḄfᔠஹ0ᑖḄ;¦UVWXYZ[\QḄᑨ;\]@⚪ᐵ_.23.᝞ᙠ\ABCDJ,EAB¿,FADÁ¿ÃDF=BE(1)CE=CFG(2)'GᙠAD¿ÃNGCE=45°,ᑣGE=BE+GDᡂÇᔩ??ூᫀ௃(1)£@᪆(2)ᡂÇூ@᪆௃É⚪ᑖ᪆(1)ᵫDF=BE,"#ABCD\.ACEB2CFD,l§yCE=CF.(2)ᵫ(1)/,CE=CF,NBCE+NECD=NDCF+NECDᓽNECF=NBCD=90°3NGCE=45°ᡠq./NGCE=NGCF,ᦑ./AECGᔠAFCG,ᓽEG=FG=GD+DF.3ÊDF=BE,ᡠq.yGE=BE+GDᡂÇ.

20É⚪@᪆(1)ᙠ\ABCDJBC=CD{ZB=ZCDFBE=DF••.ACBE“CDF(SAS)..-.CE=CF.(2)GE=BE+GDᡂÇ.ᳮᵫ:•.,ᵫ(1)/:ACBEÌCDF,.-.zBCE=zDCF,.1.zBCE+zECD=zDCF+zECD,HPzECF=zBCD=90°,X-.zGCE=45°,.-.zGCF=zGCE=45°.CE=CF1••zGCE=zGCF,GC=GC."ECGaFCG(SAS)..-.GE=GF.Í.GE=DF+GD=BE+GD.ὃ1.\Ḅឋ7G2.ᐰUfḄᑨ;Qឋ7.