1、 2017-2018 12 120 12 3 36 1 ABCD , A B 20 , C ( ) A.60 B.80 C.100 D.120 2 A B C , , ( ) A.0 3 B.2 C.3 D.4 3 1 ABCD EF AB GH AD EF GH O ( ) A.7 B.8 C.9 D.11 4 ABCD AB 5 cm BC 7 cm A.12 cm B.35 cm C.24 cm D.48 cm 5 ( ) A. B. C. D. 180 6 ABCD ,AD BC, ABCD ( ) A. A+ C=180 B. B+ D=180 C. A+ B=180 D. A+ D
2、=180 7 ABC 1 ABC 2010 A 2008 1B 2009 1C 2 2008 1D 2 2009 18 A.88 108 88 B.88 104 108 C.88 92 92 D.88 92 88 9 ABCD R P DC BC E F AP RP P BC B C R A EF B EF C EF D EF 9 10 10 A B A B A B C AC BC D E DE 10m A B A 15m B 25m C 30m D 20m 11 1440 A 30 B 36 C 40 D 45 12 135 A B C D 6 3 18 13 10 16 x _ 14 3c
3、m 5cm 6cm _cm 15 ABCD ,AB BC=1 2 24 cm, AB=_ cm,AD=_ cm 16 4 _ 17 15 _ 18 ABCD 20cm AC BD O BOC AOB 2cm CD cm 8 66 19 ABCDE A D 90 , B C E 3 8 7 B C E 6 20 ABCD A=120 AB=3 AD=5 6 (1) ADC ABC (2) BC CD 21 E F ABCD AC AE=CF 8 BFDE 22 ABCD BA E DC F BE DF AF BC H CE AD G AGE CHF 8 23 ABCD AD BC AC BD O
4、 EF O AD E BC F OE OF ABCD 8 24 A B C D E F 8 25 E DC CE DC AE BC BD F G AC BD O OF AB 2OF 12 CCCCB DDDCD BC 13 3 X 13 14 7 15 4,8 16 10 17 24 18 4 19 B=60 , C=160 , E=140 . 20. ADC=60 , ABC=60 ,BC=5,CD=3. 21. BD, . 22. .23. .24.360 25 CE/AB E= BAF FCE= FBA CE=CD=AB FCE FBA (ASA) BF=FC F BC O AC OF CAB AB=2OF
