九年级数学下册 第3章 圆 3.7 切线长定理同步测试 (新版)北师大版

1、切线长定理 ，PAPBOCDOPAPB于DPCD）PBOB EOAEBP ）POPAPBOBCOBBCA ABCD）ABBDOD AC BDPAPBOBAPBO 1POPAO于PBO于PAPB=ABCOBCDE P O MN与 BC O RtMBNPAPBOQOQOPAPB于FPEF10如图，点BOBOBOOBAACAD CDBCOOCCG）ABCDBCABCD2过AFDCEADE）CACD O 于 D CBCEO 于 E12CDCE）ABCECDcm cmABCDABCDCECE cm BC ABBCcmABCDBCBCAAEtanCBE= O ABCDABDC、N BCDA3ADBC；AO

2、DPAPBOCDOPCDAPBPACOD POPAPBOCABCOPAPBPDE ）ABCO与BCACABDDF ）ABOC是ABCDOD点BOCDABCE=4D ADADACD，GBCGDABACAEF；GADDCDDBEFCABBCCDOABCDOBCBCOOFABCACBACO交AB于 DOBCEF1= ；2ACS S ACDEDF 5CPAPBOCDOPACEDBPCDPCCDACPDB OA，BO,AOB=2=120， OAP=OBP=90， =180AOBC1 OAPOBPBOAAEB=2AOB AEBF O AFBAEB C AB BCA=AEB C AB BCA=AFBBACA

3、POACBDOBPBDAB1PBOAPOBPO= APBPAOAPB2APOPOPBOBPBcmO是RtABCODABCODBDBEOEB ODBE ODBE 6OEcmO切AB于BC于MN于NP与NE两 条 切 线 ， DM ， NPNE ， Rt MBN 的 周 长 为 ：MBBNBDcmcmcmPBOQOQO 、PB 于 E、F PA，FBPAPEF PAPB OCODOA B OCAODAAD OAC DABCBCDCDBCAB O 11OBC= ABCOCB= BCD，BE，CGOBC+OCBBOC22= BE22DAE O EFEC EFECAEADE）CE222S ADEAABC

4、ABCABACCACDO 于DCBCEO12于EBCABCECD312CADCABAB和ACOOABOACOAB=7CABABcmcm 36 3cm5 33 ODBD DEABBCDBEBDE5 335 33设xx=2225解 BC接 BE于于ABAEO于 ，BAFEAFAFAFABFAEFAOBERtABO，2FBOBAOBOtanBAOtanCBE= 5OABCD于BMDN，CMAEBEANDNCMABDCBC； OEOMONOAOAEOANOAE=OANODNODFOANODNOAEODEABDCEANCDN1OANODN= AOD28CACE O CE DEDB PDEPCPDCAPA

5、PBPAPAPCEPDEACDCDBCA，111CEOOCEOCA= ACDODE= CDBOCEODE= 222ACDCDBCOD BDADCODC， ECEBO PAPB OPAPBPDEPDPEDCECDAEBAO与BCACABDADAFCF，BECEBDCFADAFADFADDF，1ACBCAF=25 52CDOCACDBCBC ，5OD CDBE BCCDOBEOCBECDOBCEDCO125 5即=2 1 529 1 EDDGFDCDABACDACABDACDD ADADGD AB E AC FEG，FGFCAEF AFAB（ADDGAEGADBABDAGDBAD=EG AGBD AB311EAGAEGADBEG= EFEGS = = 2AEF22SS BDSDBEFCABDCABDOBC11ABBCCDOOBEOBF= EBFOCGOCF= 22GCFABCDEBFGCFOBFOCFBOCOBC是BOCBOCOBCBOCO 68ABBCCDOOFBCOF=BC10ECEDOECEDECDEDCEDCEDB1ECDEDBEDBEDEB