1、 2017-2018 2017 2018 ( ) 8 3 24 1 D 2 B 3 B 4 B 5 C 6 B 7 C 8 A 6 3 18 9 108 10 140 11 12 3 13 6 14 14 18 36 54 72 4 6 24 15 1 1 16 1 a 3=0 b 4=0 c-3=0 a=3 b=4 c=3 3 2 3 ac 4 ABC 6 17 1 3 AB=AC ADB= ADC B= C 3 2 AB=AC ABD ACD , 1 2, . AB AC AD AD ABD ACD 5 BD=CD 6 18 1 2 2 AF BC AF=BC 3 AM DAC DAM C
2、AM= 1 2 DAC ABC DAC= ABC C 4 ABC= C B= C= 1 2 DAC DAM= ABC AF BC 5 AFE= CBE FAE= ACB E AC AE=CE AEF CEB AF=BC 6 3 8 24 19 1 A B x=1 A B b= 1 a 2=2 a=4 2 A 4 1 B 2 1 3 AB=6 S ABC= 1 2 6 1=3 4 2 AB y A B a= 2 5 AB=3 |b 1|=3 b=2 b= 4 6 a= 2 b=2 a b= 4 7 a= 2 b= 4 a b=2 8 20 1 D BC 1 =180 EDC 1 1=90 1 2
3、 EDC 2=180 EDC 1 = 90 1 2 EDC 2 = 2 3 2 DB F BF=BD AF ABC=90 AB DF 4 AB DF AD=AF 2= F 1= F 5 AED ACF , 1, . EC F AD AF AED ACF 6 ED=CF=BC BF 7 ED=BC BD 8 21 1 ABC=9 PR=6 1 BP BR P O AB PB=OB=3 PBA OBA 2 R O BC RB=OB=3 RBC OBC 3 ABC=9 PBA+ OBA+ OBC+ RBC=2( OBA+ OBC)=180 P R B 4 PR=PB+BR=3+3=6 5 2 ABC
4、 9 PR6 6 1 ABC 9 PBA+ OBA+ OBC+ RBC=2( OBA+ OBC) 180 P R B 7 PRPB+BR=3+3=6 8 1 10 22 1 ABC A= B= C=60 1 BPE 2+ BPE B=18 CPD 1+ CPD C=18 1+ 2+ BPE CPD+ B+ C=36 1+ 2+ BPE+ CPD=240 1 1 P BC BPE+ CPD+ =180 BPE+ CPD=180 2 1+ 2+180 =240 1+ 2=60 + 3 2 2 2 1=60 4 2 EP AD O AOE AOE= 2 A POD POD= 1 5 AOE= POD 2 A= 1 3 2 1=60 6 3 3 2 1=60 8 4 2 1=60 10 3 1 1 4
