12.2 (SSS),AB=DE BC=EF CA=FD A= D B=E C= F,1 , ,2 ,1. 2. 3.SSS 4.,:,鱻,?,AB=DE, CA=FD, BC=EF, A= D, B=E, C= F,1.ABC DEF 2.,ABC DEF?,1.,2M,2M,45?,45?,2.,2cm,45?,:., ,3045,:.,4cm6cm ,:.,30,4cm,:., , , ,3060 90 , ,3cm4cm6cm ,ABCABC , AB= AB ,BC =BC, A C =AC.ABCABC,: 1. BC =BC;,2. B C,BA,BC,A;,3. AB AC ABC., SSS, ,?,ABCDEF,AB=DE AC=DF BC=EF,ABCDEFSSS,A,C,B,D,DBC,BD=CD,ABDACD,AB=AC,BD=CD,AD=AD,ABDACDSSS,1., ABCAB=AC,ADABCD ABDACD,B=C,B=C,ADBC,ADB=ADC=90 ADBC,裺,裺,2AC=FEBC=DEADBFAD=FBABC FDEAC=FEBC=DE,ABC FDEAB=DF, DBABDFAD=BF AD+DB=BF+DB AB=DF,1AB=ACAE=ADBD=CEAEB ADC,BD=CE BD-ED=CE-ED BE=CD,BECAB=DEAC=DFBE=CF.ABCDEF. BE=CF BE+EC=CF+EC. BC=EF. ABCDEF ABCDEF ,2. SSS,3. 衣,1.,2ABCDAB=CD,AD=CB, A= C.,ABDCDB,AB=CD,AD=CB,BD=DB,ABDACDSSS, A= C ,ABCDADBC,P37,