1、 2015 顺义区初二（上）期末数学 10 3 30 1 3 A B C D 2 3 0 x A x 3 B x 2 C x= 2 D x=3 3 3 ABC ABC A B C D 4 3 A B C D 5 3 A B 100 C D 6 3 a b c A a=3 b=5 c=7 B a=2 b=2 c= C a= b= c= D a= b= c= 7 3 3 5 7 A B C D 8 3 A B C D 9 3 a h BC=a BC MN BC D DM DA=h AB AC ABC AD=h D AD MN MN BC=a AB AC ABC A B C D 10 3 ABC A
2、D BE H BH=AC ABC A 30 B 45 C 60 D 30 45 10 3 30 11 3 x 12 3 x 13 3 1 2 3 3 14 3 2 m m 15 3 + 1 “2 1 ” 2 16 3 ABC ACB=90 ABC=60 BD AB DAC=50 D 17 3 2 18 3 m n=3mn 19 3 2 6 n n 20 3 30 10 12 60 21 4 22 5 + 23 5 24 5 AB CAD C= D=90 AC=AD 25 5 x+2= 26 4 x=3+ y=3 x 2 y+xy 2 27 5 E AB AD AB BC AB DEC DEC=
3、90 AB=AD+BC 28 5 8 1 000 600 29 5 ABC ACB=90 D BC DE AC DE=AC AC=2 AD=4 ACEB 30 5 ABC AB=AC=6 A=45 D AC E BD ABD CDE BCE 1 EBC 2 BE 31 5 x 2 3x+1=0 32 7 ABC BM A BM D AD CD CD BM E 1 1 ABM=30 BCE 2 2 60 ABM 90 BM CD 参考答案与试题解析 10 3 30 1 = C 2 0 x 3=0 x+2 0 x=3 D 3 ABC 180 90 ABC A 4 A =3 3 B = =15 9
4、C D =7 D 5 A A B 100 B C C D D C 6 A 3 2 +5 2 7 2 B 2 2 +2 2 = 2 2 C 2 2 + 3 2 3 2 D 2 + 2 2 B 7 3 5 7 =3+5+7=15 = = B 8 A = B C = =a b D = C 9 AD BC AB=AC ABC AD BC BC ABC A 10 ABC AD BE AD BE H ADC= BEC=90 EBD+ BHD=90 AHE+ HAE=90 BHD= AHE EAD= EBD BH=AC ADC= BDH=90 BDH ADC BDH ADC AAS BD=AD ADB=90
5、 ABC=45 B 10 3 30 11 3x+2 0 x 12 x 2 0 x 2 x 2 13 1 2 3 6 3 3 3 = = 14 2 3 =8 2 8 m=8 8 15 2+1=3 2 1=1 2 1=2 2 1=2 2 = = 16 ABC=60 BD AB DBC=90+60 =150 ADBC 360 D=360 ACB DBC DAC=360 90 150 50 =70 70 17 D BC BD=DC=1 Rt ABD AB=2 BD=1 AD= = ABC BC AD= 2 = 18 = m n=3mn = = = 19 =2 = 6 =2 n 2 20 1 BC=10
6、 AD BC D B C A D= 3 0 AD=6 AB=AC AD BC BD=DC=5 AB=AC= = AB=AC=10 BD AC D BD=6 AD= =8 BC= =6 10 6 10 6 12 60 21 = =6 2=4 22 = + 3 = 5 = 7 23 1=2x 1+4 x= 1 x= 1 24 AB CAD CAB= DAB ACB ADB ACB ADB AC=AD 25 = =x+1 x+2= x= 2 =x+1= 1 26 x=3+ y=3 x 2 y+xy 2 =xy x+y = 3+ 3 3+ +3 = 9 4 6=30 27 AD AB BC AB DE
7、C=90 AED=90 BEC BCE=90 BEC AED= BCE DEC DE=CE ADE BEC ADE BEC AE=BC AD=BE AB=AD+BC 28 x x 8 = x=20 x=20 x x 8 0 x=20 x 8=12 10 12 29 DE AC DE=AC ACED DE=AC=2 Rt ACD CD= =2 D BC BC=2CD=4 ABC ACB=90 AB= =2 D BC DE BC EB=EC=4 ACEB =AC+CE+EB+BA=10+2 30 1 AB=AC=6 A=45 ABC= ACB=67.5 ABD AD=BD ABD= A=45 EB
8、C= ABC ABD=22.5 2 A= ABD=45 ADB= CDE=90 AB=6 BD= AB c o s 4 5 = 3 DE=x CD=DE=x EC= = x BE=EC= x x+x=3 x=6 3 BE=6 6 31 x 2 3x+1=0 x+ =3 2 =x+ +2=5 = 32 1 1 BD 1 BM AD ABM=30 ABC BDA AD BC AD=BC DA=DB ADBC ACB=60 BCE=30 2 BM CD AE BC F BD=BA BA=BC ED=EA BDA= BAD EDA= EAD BD=BC BDC= BCD EDB= EAB BCD= EAB EFC= BFA ABC=60 CEA= ABC=60 AEC+ AEM+ DEM=180 DEM= AEM DEM=60 BM CD 60
