天津市紅橋區(qū)九級數(shù)學(xué)上學(xué)期期末考試試題

天津市紅橋區(qū)2017屆九年級數(shù)學(xué)上學(xué)期期末考試一試題2016~2017123361A2A3B4D5C6D7C8D9B10A11C12D6318133142152:31001637.517318107661981ABCDA1222412AB2AB2=1612632AB4AB4=181232081△ADF△ABEADAB902△ADF

A

90°△ABE

3AE

AF

4

AEB

F60ABE

90﹣60

30ABCDADAB43ABD45DE434EBDABDABE15821101x23x40x1x4AB(10)(40)22yx23x4yC(04)1B(40)BCykxb4kkbb44BCyx43yx23x4x32BCDD35()22PP(3m)2PD|m5|2S△PBC14OB?PD2

14|m5|=422m91m22PyPCDPBAOx

3931()(2)222

第（21）題22101ODDFODDFODF90ABCCA60ODOCODC60ODCAODPABDFAB52RtADFA60ADF30AD2AF224OD∥ABOBCODABCADCD4AC8AB8BFABAF6FGBCBGF90RtBFG

BFGFG

3033

BG

3

10AFE

DBGOC第（22）題23101A(22)ykk4xy41xB(1n)y41n4n82x2B122A(22)B(1n)yaxb222aba1a44b108b2y4x1052y4x10my4x10m6y4x10my4x4x10m44x2(m10)x407x(m10)2640m2m181024101ABACA36ABCC72BEABCABECBE36BEC180CCBE72ABEABECCAEBEBEBCAEBC32ACABEF∥BCAEAFlEACFABAEAFAN(E')CAE△BAF36°ACM(E')ABFEE'ACF'ABAE'AF'BCCAEBAF第（24）題CEBF63CE∥AB1AEBC△AEFAECABlMNEEMABCMBAMABC72BAC36CAM36EENAB∥lAMNBAM72AMANANMAMN72MAN18027236CANCAMMAN7236°72°CE∥AB1025101A(40)B(13)yax2bx016aa3abb4yx24x22C(33)B(13)BC2S△ABC1233323PPDBHBHDP(mm24m)BHAH3HD24mPDm1mS△ABPS△ABHS四邊形HAPDS△BPD61331(3m1)(m24m)1(m1)(3m24m)2223m215m0m10m25P(55)64CMNMMx2CMMNCMN90CBMMHNBCMH2BMHN321M(12)N(20)CM22125S△CMN155522MMx3RtNEMRtMDCRtNEMRtMDC∴EMCD5，MDNE2，由勾股定理得：CM225229，∴S△CMN1292929；22③以點N為直角極點且N在y軸左側(cè)時，如圖4，CNMN，MNC90，作輔助線，同理得：CN325234，∴S△CMN1343417；2④以點N為直角極點且N在y軸右側(cè)時，作輔助線，如圖5，同理得：CN321210，∴