1、A20 B25 C30 D357如图,直线ab,直线c分别交a,b于点A,C,BAC的平分线交直线b于点D,若150A50 B70 C808如图,AOB的两边OA,OB均为平面反光镜,AOB40在射线OB上有一点P,从P点射出一束光线经OA上的Q点反射后,反射光线QR恰好与OB平行,则QPB的度数是()A60 B80 C100 D120二填空题9如图,已知ABCE,B50,CE平分ACD,则ACD 10如图,已知ab,直角三角板的直角顶点在直线a上,若130,则2等于 11如图,ABCD,AF交CD于点E,若CEF13823,则A 12如图,BCA64,CE平分ACB,CD平分ECB,DFBC
2、交CE于点F,则CDF的度数为 13如图,已知AFCE,ABCD,A67,则C 14如图,ab,295,3150,则1的度数是 15如图是长方形纸带,DEF,将纸带沿EF折叠成图,再沿BF折叠成图,则图中的CFE的度数是 16如图,把一张长方形纸片ABCD沿EF折叠后,点A与点A重合(点A在BC边上),点B落在点B的位置上,若DEA40,则1+2 三解答题17如图,AOCD,OBDE,O40,求D的度数(1)请完成下列书写过程AOCD(已知)O 40( )又OBDE(已知) 1 (2)若在平面内取一点M,作射线MPOA,MQOB,则PMQ 18如图,ABCD,FGB154,FG平分EFD,求A
3、EF的度数19如图ABCD,B62,EG平分BED,EGEF,求CEF的度数20如图,EFAD,EFBC,CE平分BCF,DAC120(1)求ACB的度数;(2)若ACF20,求FEC的度数 21已知,直线ABCD,EFG90(1)如图1,点F在AB上,FG与CD交于点N,若EFB65,则FNC ;(2)如图2,点F在AB与CD之间,EF与AB交于点M,FG与CD交于点NAMF的平分线MH与CNF的平分线NH交于点H若EMB,求FNC(用含的式子表示);求MHN的度数参考答案1解:两平行线AB,CD被CE所截,1+BEC180,170BEC1801180701102BEC,2110选:B2解:
4、12,ab,45,5180355455C3解:ABE150ABC30又ABCD,ABCBCD30CE平分ACD,ACD2BCD60A+ACD180A180ACD180601204解:BCAD,1235又CA平分BCD,2335则BCD70D180BCD180D5解:如图,由题意知:ABCD,FEG9023,1+3+901801+2901402506解:CDAB,AOD+D180AOD70DOB110OE平分BOD,DOE55OFOE,FOE90DOF905535AOF70357解:BAC的平分线交直线b于点D,BADCAD,直线ab,150BADCAD50218050808解:QROB,AQR
5、AOB40,PQR+QPB180AQRPQO,AQR+PQO+RQP180(平角定义),PQR1802AQR100QPB1801009解:ABCE,B50ECDB50ACD2ECD250100答案为:10010解:给各角标上序号1+3+4180,130,390460ab,24606011解:CEF13823,FED180CEF180138234137,ABCD,AFED41413712解:BCA64,CE平分ACB,BCF32CD平分ECB,BCD16DFBC,CDFBCD161613解:如图:AFCE,A671A67C1676714解:过点C作CDa,CDab,1+ECD180,3+DCF1
6、802951+2+33601360233601509511511515解:ADBC,BFEDEF,CFE180DEF180,CFGCFEBFE1801802,CFECFGBFE1802180318016解:ADBC,DEA40EAF40又BAEBAD902904050由折叠可得,1AEA(180DEA)701+270+5012017解:(1)AOCD(已知),O140(两直线平行,同位角相等),又OBDE(已知),D140(两直线平行,同位角相等)1,两直线平行,同位角相等,D,40,两直线平行,同位角相等;(2)若在平面内取一点M,作射线MPOA,MQOB,则PMQ(40或140)(40或1
7、40)18解:ABCD,FGB154GFD180FGB18015426FG平分EFD,EFD2GFD22652AEFEFD5219解:ABCD,B62BEDB62EG平分BED,DEGBED31EGEF,FEG90DEG+CEF90CEF90DEG90315920解:(1)EFAD,ADBC,EFBC,ACB+DAC180DAC120ACB60(2)ACF20FCBACBACF40CE平分BCF,BCE20EFBC,FECECB,FEC2021解:(1)EFG90,EFB65BFD906525FNCBFD2525;(2)如图1,过F作FPAB,连接EG,ABCDFP,MFPEMB,又EFG90PFN90FPCD,FNCPFN90;如图2,过F作FQAB,ABCDFQ,MFQAMF,QFNCNF,AMF+CNFMFQ+QFNEFG90过H作HRAB,ABCDHR,AMHMHR,HNCNHR,又MH平分AMF,NH平分CNF,AMHAMF,HNCCNF,MHNMHR+NHRAMH+HNC(AMF+CNF)9045
copyright@ 2008-2022 冰豆网网站版权所有
经营许可证编号:鄂ICP备2022015515号-1