新湘教版九年级下册数学全册教案

1、mm或mmm(，顶点是(mmml，则lllleqoac(,A)bbbbbbbbblllllllllllll）和（eqoac(,)），eqoac(,S)（元），bbeqoac(,S)eqoac(,=S),.,.,.,.,.,.:,A.,.,.:,.,dd=rd.(:ABAC)AB).:,.:,.,AB,:AB.:.,.,.:.:,.:,.:.,.),.,.,.ABCAA.AB.AC.AAAA_.AB,_.AAB,_.,AB=_._.,.,.,.:.,.,.,:,.,.,:.:A,A=A.AABB,AB=B.,:AB,A,AB,B,=,:,.,.:,.eqoac(,)ABC,CAAB.,.:.,.

2、,._AB_.,_.AEB.:.:.,.,.,.,.,.,.,._.,_,_.,_.,:.:.,.,.,BACABBACBAC.,.,.AE,BOE:,:.:.,.:;.AB,.,A,ABAC.,中，,CABCAB.,.,.35.,.,.:.,.,.,.:,.,.AB,=,.,.,;.,AB.,BAC=_DAC=_.BAC.,.,ABE,AEC.ABBC.ABAC,;,ABC,EACBC,ABD:,BC.ABDABCBC.ABAC,AABADC=_.,AB,.,_.ABBDCEABECEF.,CE_.AB,A,AB,A,AB,.CE.:;,.79.,.,.,.,.,.，.,:ABAB，.,，.

3、AB,，.,.:AB,AB,AB.:,.):,.,.:AB(AB,AB:,AB.,AB,:AB,AB,.ABAB.EFAB,BE.CEDE.EFAB,BE.CEDE.CEBEDE.ABABOM=AB.,:ABAB.ABEFABEF.ABABEk=_.ABACABACE.,.:AB,ACAB,.AB,.:.,.,.,.,A,B,C.,.,:,.,AAAB,.A,A,A,.A,B,AB,AB.,ABC,A,B,C.AB,AB,.A,B,C,AB,BC,CA,A,B,.:.;.ABC.ABC,.:,.:.,A,B,C,.,).ABC,.,.,eqoac(,)ABC.A.AB.ABC.ABABbABC

4、ABCA.B.C.A.B.C.,.,.,.,.,.,.,.,.dd=rdl.l.l,.l,.:,.lddddd=rd.,.CA.CAd,CA.ABCABABAB.llA.B.C.ldldll_.ABC.ABr_r_.ABCABABd.=解：（AB,ACBCAB.dABdAB.ldldld=rld.,.,.,.,.,.,.,.,:,AB,lAlABlAldlldl.,.APB.,BC.,.,.:APB,.;.A.C.B.A.B.C.eqoac(,3.)ABCABBCDEACACE.:DE.BCABBCEF,AC.,.:C,C,AC,DEC.DEAC,DEDE.:AC,BC,BAC.ABAB,AC

5、.,:,.23.,.,.LAl.AB,BCACEACAC.BCABABCDBC,AB=，以A.B.C.ABABEEABABABAB.ABCBCACFECFBEACABCBE:ABBE.,.,.,:,:AB.,.,.:,.AB.:.:,.CACBABBD.BD.AB,AB.BD.AB.:AB.CA,CB,A,B,AB.,AB,BD.ABE,.,.:CACEAE,DEDBEB,AB,AC,BAC_.ABAB_.,A,B,D,E,BCC,_.,AD,DC,BC,BC,DOC=_.,AB,DEE,C,F,BE;.,.DE,ABE,BE.BCCE,F.,.,.eqoac(,)ABC,ABC.:,:.:B

6、I,I.I,IBC,IABC.,.,.,ABC,.:ABC1=ABC,2=ACB.1+ACB).ABC_.BC,OEAB,，点BC,.:.A.B.C.eqoac(,)ABCEF,ABCABC.ABCABCABBCACEFABC_.eqoac(,4.)ABCBCACABEFAFCE.,EABC,AEABC.,.:BE,EABC,CBE,ABE,CBD,EBD,.,.,.,.,.,AB.ABABAB.lnlncm.ln,_.,.l=_.Rl=_.:lnrrl.(.eqoac(,)ABC,CA.,.:,.=.AA=,.ABCAB.AACB.ACA.AAA.AAA.C.ABFAA.BC.B.Bl,Rn

7、B.A.nB.lC.ABBBCBB_.,l.ln.,.,.,.,.,.,.;.R_._.R=,=,l.,).cm,l,R=.:=.,AC.:,.:F,E.eqoac(,=S),AECBFD.ABAB.AB_.eqoac(,4.)ABCABCABAC_).RABBBCCED.eqoac(,+S)BCDBCED=.=.(l.,.,.,.,.,.,ABCDEF.:,.,.,!,.:,.,.,.,.,.,:,.A.B.C.ABCDEACAPBA.B.C._.,ABCDEACBEF.ABFBCF,.,:.,.,.,.,.,.,.:,.:,.:.,.:,.,.:.:,.l.,.,.ABA.ABB.C.AB

8、.eqoac(,)已知AB,ACBCE,F,CBBFGBGFGEED).ACAC.,:GCACBGF.,BGF,.eqoac(,=S)=g).ABC.AB.AC.ACAC,.BBEE,=BEAB.bBEbBE.(,).ACbbAC.ABAB，若AB=_.,ABAC,B,BDC=_.ABC,ABACABCBeqoac(,A)BC_.ABABABAFAAFE.E.eqoac(,).AC,AC,EBA,=OA,+8,AFAAF.ABD,EA=EB.,+4,E.:.,.,.,.:.(.:.:.:.ABABBE.AEAE.:CFAEF:.ABBE.AECF.:EAFC.A.B.C.A.B.C.A.B.C.A.B.C._.5m.AAB:.,.AB).ABABBABABABABABA.ABCD.A.B.C.A.B.C._.ABCD(BCABABABBAB.ABBABBABH._._.).nABn6=6ab=6ab+3b=.=l=+l._.P._.d=e=1bb1+1+2+1+1=6b1+1+2+2+1=7b.A.B.C._.).AB.A.BC.eqoac(,在)ABCCAB.BAC.A.B.C.ABC_.AB1