1、 1 9 1 A B C D 2 l1 AB l2 2 A B C D 3 6 6 1 N 2 N A 1 B 1 C 2 D 2 4 ABC BC DCE AD BD AC ACED 2 A 0 B 1 C 2 D 3 5 A B C D 6 ABC B E DEF BC=5 EC=3 A 2 B 3 C 5 D 7 7 A B C D 8 ABC BC 2cm DEF ABC 16cm ABFD A 16cm B 18cm C 20cm D 22cm 9 ABC A 3 1 AC 3 A B C D 6 10 ABC AB=AC BC BAC AD ABC A BC BC 11 5 ABC
2、 BC DEF BC ACED 12 ABC AB=4 BC=6 ABC BC 2 13 280m m 4 14 8 ABC BC 1 DEF ABFD 15 12 ABCD AC ABC AD 32 5 16 AB A 5 1 B 2 3 CD C 5 1 D 2 3 1 AB CD 2 AB A1B1 A A1 1 2 A1B1 B1 17 1 AOB 1 B y 5 2 AOB 3 A1O1B1 A1O1B1 3 2 A1 18 1 ABC ABC x 5 O 1 2 ABC 19 ABCD AB=6 1 ABCD AB 5 A1B1C1D1 2 A1B1C1D1 A1B1 5 A2B2
3、C2D2 n An 1Bn 1Cn 1Dn 1 An 1Bn 1 5 AnBnCnDn n 2 1 AB1 AB2 2 ABn 56 n 20 A1B1C1 ABC 4 A1 1 1 B1 4 2 C1 3 4 1 ABC A B C 2 AOA1 6 7 2016 9 1 A B C D A B D C C 2 l1 AB l2 2 A B C D l1 AB l2 l1 l2 2 B 3 6 6 1 N 2 N 8 A 1 B 1 C 2 D 2 1 2 N 2 D 4 ABC BC DCE AD BD AC ACED A 0 B 1 C 2 D 3 ABC DCE ACB= AC=CD
4、ACB ACD AD=AC=BC AD=BC AB=CD ABCD BD AC AD=AC=CE=DE ACED 3 D 9 5 A B C D C C 6 ABC B E DEF BC=5 EC=3 A 2 B 3 C 5 D 7 =BE=5 3=2 A 7 A B C D 2a+2b 2a+2b 10 2a+2b D 8 ABC BC 2cm DEF ABC 16cm ABFD A 16cm B 18cm C 20cm D 22cm 16cm ABC BC 2cm DEF AD=CF=2cm BF=BC+CF=BC+2cm DF=AC AB+BC+AC=16cm ABFD =AD+AB+B
5、F+DF=2+AB+BC+2+AC=20cm C 9 ABC A 3 1 AC A B C D A 3 1 AC O AO=OC=2 AC + B AC AC 11 D 6 10 ABC AB=AC BC BAC AD ABC A BC BC ABC AB=AC BC BAC AD ABC A BC BC 11 5 ABC BC DEF BC ACED 15 12 A BC h S = BC 2 AD=2BC CE=BC ACED = AD+CE 2BC+BC 5=15 15 12 ABC AB=4 BC=6 ABC BC 2 12 12 13 280m 140 m 13 280 2=140
6、m 140 14 8 ABC BC 1 DEF ABFD 10 8 ABC BC 1 DEF AD=1 BF=BC+CF=BC+1 DF=AC AB+BC+AC=8 ABFD =AD+AB+BF+DF=1+AB+BC+1+AC=10 10 15 12 ABCD AC ABC AD 32 4 8 AC H x x 12 x =32 x=4 8 8cm 4 8 14 5 16 AB A 5 1 B 2 3 CD C 5 1 D 2 3 1 AB CD x 2 AB A1B1 A A1 1 2 A1B1 B1 4 4 1 A 5 1 C 5 1 AC x x BD x x AB CD x x 2 A
7、 5 1 A1 1 2 A 6 B 2 3 B1 4 4 A1B1 15 4 4 17 1 AOB 1 B y 3 2 2 AOB 3 A1O1B1 A1O1B1 3 2 A1 2 3 1 B y 3 2 2 A1O1B1 3 A1 2 3 1 3 2 3 2 3 16 18 1 ABC ABC x 5 O 1 2 ABC 1 1 5 4 0 1 0 2 ABC =S AABB+S + 5+ 3 5=25+ = 19 ABCD AB=6 1 ABCD AB 5 A1B1C1D1 2 A1B1C1D1 A1B1 5 A2B2C2D2 n An 1Bn 1Cn 1Dn 1 An 1Bn 1 5 A
8、nBnCnDn n 2 1 AB1 AB2 2 ABn 56 n 1 AB=6 1 ABCD AB 5 A1B1C1D1 17 2 A1B1C1D1 A1B1 5 A2B2C2D2 AA1=5 A1A2=5 A2B1=A1B1 A1A2=6 5=1 AB1=AA1+A1A2+A2B1=5+5+1=11 AB2 5+5+6=16 2 AB1=2 5+1=11 AB2=3 5+1=16 ABn= n+1 5+1=56 n=10 20 A1B1C1 ABC 4 A1 1 1 B1 4 2 C1 3 4 1 ABC A B C 2 AOA1 1 A 3 1 B 0 2 C 1 4 2 S = 4 1=2
