1、 1 27 2017 1 30 1 AB O CD AB E AB=8 AE=1 CD A B 2 C 6 D 8 2 O AB CD AB CD E CO AD BAD=20 A AD=2OB B CE=EO C OCE=40 D BOC=2 BAD 3 CD O AB CD M AB=12 OM MD=5 8 O A 2 6 B 1 3 C D 4 AB O CD AB P AP=2 BP=6 APC=30 CD A B 2 C 2 D 8 5 A B C ABC 2 27 A AB AC B AB AC C AB AC D BAC ABC 6 “ ” AB=CD=0.25 BD=1.5
2、AB CD A 2 B 2.5 C 2.4 D 2.1 7 13cm 8cm AB A 10cm B 16cm C 24cm D 26cm 8 ABCD O AC BAD A AB=AD B BC=CD C D BCA= DCA 9 A C 3 B BA BC ABCD D A 2 B 2 C 2 D 2 3 27 10 Rt ABC ACB=90 A=56 BC O AB D E O = OE E EF OE AC F F A 92 B 108 C 112 D 124 11 AB O CD AB BCD=30 CD=4 S = A 2 B C D 12 AB O CD H cos CDB=
3、BD=5 OH A B C 1 D 13 A B C O AC OB BAO=25 BOC A 25 B 50 C 60 D 80 14 O AB CD P A=42 APD=77 B 4 27 A 43 B 35 C 34 D 44 15 AB O C D E O AED=20 BCD A 100 B 110 C 115 D 120 16 ABC O A = OBC A 180 2 B 2 C 90+ D 90 17 O = D O CDB=25 AOB= A 45 B 50 C 55 D 60 18 AB O CD O ACD=30 BAD A 30 B 50 C 60 D 70 19 O
4、 OA BC AOB=70 ADC 5 27 A 30 B 35 C 45 D 70 20 A B C O AOB=72 ACB A 28 B 54 C 18 D 36 21 AB O C D O AB ACD A ADC B ABD C BAC D BAD 22 A B C O AOB=70 ACB A 30 B 35 C 45 D 70 23 B C A AB A E F AC D BFC=20 DBC= A 30 B 29 C 28 D 20 24 O AB AC OC ACO=30 BOC 6 27 A 30 B 45 C 55 D 60 25 O AB CD CAB=36 BCD A
5、 18 B 36 C 54 D 72 26 O AB CD E A=15 2 CD A 2 B 1 C D 4 27 A B C D O B M OD BDC=40 AMB A 45 B 60 C 75 D 85 28 A B C O C AB AOB=64 ACB A 26 B 30 C 32 D 64 29 O OD AB C AO O E BE CE AB=8 CD=2 BCE 7 27 A 12 B 15 C 16 D 18 30 O AB O AB=10 = = E D AB M AB BOE=60 CED= DOB DM CE CM+DM 10 A 1 B 2 C 3 D 4 8
6、27 2017 1 30 1 2 0 1 7 AB O CD AB E AB=8 AE=1 CD A B 2 C 6 D 8 M2 KQ OC OE=OB AE=4 1=3 CE=ED= = CD=2CE=2 B 2 2 0 1 7 O AB CD AB CD E CO AD BAD=20 A AD=2OB B CE=EO C OCE=40 D BOC=2 BAD M2 = CE=DE BOC=40 OCE AB CD 9 27 = CE=DE BOC=2 BAD=40 OCE=90 40 =50 D 3 2 0 1 7 CD O AB CD M AB=12 OM MD=5 8 O A 2 6
7、 B 1 3 C D M2 OA AM= AB=6 OM=5x DM=8x OA=OD=13x OA= 13 OA CD O AB CD AM= AB=6 OM MD=5 8 OM=5x DM=8x OA=OD=13x AM=12x=6 x= OA= 13 O = 2 O A =1 3 B 10 27 4 2 0 1 7 AB O CD AB P AP=2 BP=6 APC=30 CD A B 2 C 2 D 8 M2 KO 30 KQ OH CD H OC OH CD HC=HD AP=2 BP=6 OA=4 OP=OA AP=2 Rt OPH 30 OH= OP=1 Rt OHC CH=
8、CD=2CH=2 OH CD H OC OH CD HC=HD AP=2 BP=6 AB=8 OA=4 OP=OA AP=2 Rt OPH OPH=30 POH=30 OH= OP=1 Rt OHC OC=4 OH=1 CH= = CD=2CH=2 C 30 5 2 0 1 7 A B C ABC 11 27 A AB AC B AB AC C AB AC D BAC ABC K2 ABC ABC ABC B 6 2 0 1 7 “ ” AB=CD=0.25 BD=1.5 AB CD A 2 B 2.5 C 2.4 D 2.1 M3 OF AC E O R OF AC E BD O OF BD
9、 ABDC AC BD OE AC EF=AB O R Rt AOE AE= = =0.75 OE=R AB=R 0.25 AE 2 +OE 2 =OA 2 12 27 0.75 2 + R 0.25 2 =R 2 R=1.25 1.25 2=2.5 2.5 B 7 2 0 1 7 13cm 8cm AB A 10cm B 16cm C 24cm D 26cm M3 BC O OD AB C O D CD=8 OD=13 OC=5 OB=13 Rt BCO BC= =12 AB=2BC=24 C AC 8 2 0 1 7 ABCD O AC BAD 13 27 A AB=AD B BC=CD
10、C D BCA= DCA M4 A ACB ACD AB AD B AC BAD BAC= DAC BC=CD C ACB ACD D BCA DCA B 9 2 0 1 7 A C 3 B BA BC ABCD D A 2 B 2 C 2 D 2 M4 L8 B AC AO E BD= 2 3=2 BD= 2 3=4 OD=1 OE=2 DE=1 OD B AC AO E B BD AC D BD= 2 3=2 OD=OB BD=1 ABCD DE= BD=1 OE=2 14 27 OD CE= = CD= = BD= 2 3=4 OD=1 OE=1 DE=2 OD CE= = =2 CD=
11、 = =2 D 10 2 0 1 7 Rt ABC ACB=90 A=56 BC O AB D E O = OE E EF OE AC F F 15 27 A 92 B 108 C 112 D 124 M4 L3 COE ACB=90 A=56 ABC=34 = 2 ABC= COE=68 OCF= OEF=90 F=360 90 90 68 =112 C OCE 11 2 0 1 7 AB O CD AB BCD=30 CD=4 S = A 2 B C D M5 M2 MO CE=ED=2 DOE=60 OD OE S =S ODB S DOE +S BEC CD AB E AB O CD
12、AB CE=ED=2 BCD=30 DOE=2 BCD=60 ODE=30 OE=D Ec o t 6 0 =2 =2 OD=2OE=4 S =S ODB S DOE +S BEC = OE DE+ BE CE= 2 +2 = 16 27 B 12 2 0 1 7 AB O CD H cos CDB= BD=5 OH A B C 1 D M5 T7 OD AB CD DH=4 BH= =3 OH=x OD=OB=x+3 Rt ODH OD AB O CD H AB CD OHD= BHD=90 cos CDB= = BD=5 DH=4 BH= =3 OH=x OD=OB=x+3 Rt ODH x 2 +4 2 = x+3 2 x= OH= D
