1、 2015 门头沟区初二（上）期末数学 12 2 24 . 1 2 x A x 3 B x 3 C x 3 D x 3 2 2 A B C D 3 2 A 0 B 1 C 2 D 3 4 2 A B 1 100 C D CBA 5 2 3 A B C D 6 2 2 5 A 7 B 9 C 12 D 9 12 7 2 a b 10 A B 10 C 10 D 100 8 2 A =3 B = C = D + = 9 2 m A 0 m 1 B 1 m 2 C 2 m 3 D 3 m 4 10 2 A B 3cm 4cm 5cm C D 11 2 AB+AC=9 D AB D BC ACD A
2、7 B 9 C 11 D 13 12 2 Rt ABC AB=9 BC=6 B=90 ABC A BC D MN BN A B C 4 D 5 6 3 18 13 3 0 x 14 3 x 15 3 70 16 3 C BE AB DC AB=EC 17 3 a b 18 3 ACB C=90 AB=4 AC=2 C CP 1 AB P 1 Rt CP 1 B P 1 P 1 P 2 CB P 2 Rt P 1 P 2 B P 1 P 2 = P n P n + 1 = 14 19 28 5 29 30 6 31 32 8 19 5 20 5 21 5 22 5 23 5 24 5 F C B
3、E BF=CE AB=DE B= E A= D 25 5 x 2 +2x 8=0 26 5 ABC AD BC D AD=BD C=65 BAC 27 5 9 1 “ ” 2 “ ” “ ” 3 “ ” 28 5 S P P S A B P 1 2 29 6 28 1200 400 30 6 1 AB MN A B M N 1 ABCD ABCD MN A D B C 2 ABCD 31 8 x 2 x 4 0 “ ” x 4 x 2 x 2 x 4 0 x 4 x 2 1 x 2 x 4 0 2 3 32 8 1 “ ” Rt ABC C=90 CP CP= AB P ABC AB A B
4、A B CP E F Q AB 1 2 P Q AE BF QE QF 2 3 P AB Q QE QF 3 4 P BA 2 参考答案与试题解析 12 2 24 . 1 x 3 0 x x 3 A 2 A = B =3 C D =|x| C 3 D 4 A B 1 100 C D CBA B 5 = = C 6 5 =5+5+2=12 2 5 12 C 7 10 B 8 A =3 A B = = B C = = C D D D 9 9 13 16 3 4 m 3 m 4 D 10 A A B 3cm 4cm 5cm cm B C C D D A 11 AB+AC=9 D AB D BC BD
5、=CD ACD =AD+CD+AC=AD+BD+AC=AB+AC=9 B 12 BN=x DN=AN=9 x D BC BD=3 Rt BDN x 2 +3 2 = 9 x 2 x=4 BN 4 C 6 3 18 13 x 2 4=0 x+2 0 x=2 2 14 3 x 0 x 3 x 3 15 1 70 = 180 70 2=55 2 70 70 180 70 70 =40 55 55 70 40 16 AB DC B= DCE AB=EC CBA DCE ASA A= E CBA DCE AAS ACB= D CBA DCE SAS CB=CD A= E ACB= D CB=CD 17
6、a 0 a b 0 =a a b =b b 18 Rt ABC AB=4 AC=2 sinB= = B=30 A=60 CP 1 AB CP 1 =ACsinA=2 = ACP=30 P 1 P 2 CB P 1 P 2 AC CP 1 P 2 = ACP=30 P 1 P 2 =CP 1 cos30 = = P 2 P 3 AB CP 1 P 2 P 3 CP 1 P 2 = P 1 P 2 P 3 =30 P 2 P 3 =P 1 P 2 cos30 = = 2 P n P n + 1 = n n 14 19 28 5 29 30 6 31 32 8 19 =1+2 4 +9=12 5 2
7、0 = = 21 =2 2 =2 +2 = + 22 = = = 23 x x 1 x 2 2 x 1 =x x 1 x 2 2x+2=x 2 x x 2 x 2 2x+x= 2 x= 2 1 x=2 x=2 x x 1 x x 1 =2 2 1 =2 0 x=2 24 BF=CE BC=EF ABC DEF ABC DEF SAS A= D 25 = = = = = x 2 +2x 8=0 x 2 +2x=8 = 26 ABC AD BC D AD=BD BAD=45 C=65 CAD=90 65 =25 BAC= BAD+ CAD=45+25 =70 27 1 “ ” 2 “ ” “ ”
8、3 28 1 2 29 x x+28 x=14 x=14 x+28=42 14 42 30 1 2 ABCD AB+BC+CD+AD= +2 + +3 =2 +5 31 1 x 2 x 4 0 2 x 4 2 0 3 x 1 x 3 0 x 1 x 3 32 1 1 P Q AE BF AE BF QE QF AE=BF Q AB AQ=BQ AE CQ BF CQ AE BF AEQ= BFQ=90 AEQ BFQ AEQ BFQ AAS QE=QF AE BF QE=QF 2 QE=QF 2 EQ BF D 1 AE BF AEQ= BDQ AEQ BDQ AEQ BDQ AAS EQ=DQ BFE=90 QE=QF 3 P BA AB 2 EQ FB D 3 1 AE BF AEQ= BDQ AEQ BDQ AEQ BDQ AAS EQ=DQ BFE=90 QE=QF
