2020-2021学年北师大版八年级下册数学 第一章 三角形的证明 单元测试

第一章三角形的明单元测试一选题ABCABADDCBADA36

B

C64

D77ABC70A40

B55

C65

D70eq\o\ac(△,Rt)ABC90B30CDABAD3ABA3B6C9cmD12ABCD90ABBDBBDAEAECEAAECEBCED2DBCBCBD

ABCDDEAEDCC2B

BDACBDBADEABCcmABCACBODBCDODcmA242730Deq\o\ac(△,Rt)ABCBACACBEAEAEBA30

B35

C45

D35ADDEEACEDF①ADABC

131311131311233167ABCEDFDABAE+BFA4

B3

C2

D10MONAOMeq\o\ac(△,A)eq\o\ac(△,)Aeq\o\ac(△,A)eq\o\ac(△,)Beq\o\ac(△,A)eq\o\ac(△,)AA6BCD64ABCADDBBAC12DBCAD213ACDEEBC

14xOy22PP

15FABFEAC12AE16BACABCAEDFAEDF17BDBCEBDFCFACF48

△2△218ABCABACBAC19ABCACBO

20MBCNCBCPBCABC7.5ABC

214012

22ABCDADCD122BCAEADAE23eq\o\ac(△,Rt)90CABBAD12ACEACDBDE24CABADD，DEABB25eq\o\ac(△,Rt)906AB10BCDECE

2690ADBACEACDF1EB2AEAF27ABCACBEACADEAEDDE1C2ABCACB3BCCDE

参考答案一选题ABCADDCABADBAD26BADB26C77CC70AB180BBAC70Ceq\o\ac(△,Rt)ABCCD90BADeq\o\ac(△,Rt)ACDACeq\o\ac(△,Rt)ABC2ACcm12DBCDEBDDEBD

OABOBC2OABOBC2BEBCBD+ADBDCDADCDDACDEADBDBBADADEBDEBDOEABEOFFOAOBODABOEODOFOD3SS+△△△

eq\o\ac(△,S)

OACOE+OD+OFAB+AC18△

CAFEGHCEACBBEEHEHACEGABCAB140ACBCAB40ABCABH130ABD180EABCABCFBDBFCCABCADBCCDBD①正DDHABHACDH

1111111211212234DEDHBFDEACDFBFDHDFDEDFADHADEADHHLAHBHBFAH+AE10eq\o\ac(△,A)eq\o\ac(△,)B122MON112030356090MON1OA1eq\o\ac(△,A)eq\o\ac(△,)Aeq\o\ac(△,A)eq\o\ac(△,)6060

11223122211223122212332333124415566771267677667460BBB1730522BBA44A88ABA16A2BBA

C

32

ADDBBBADBBADBAC105

++1802180BBAD25

2512AED+BADADAEDADEBCB+BADCDE21213AB11BE11171711cm14515ABCFABABC6A60AC

3016ABADABCADBCBADCADBACDAEBAD30DFFBAEDAEFADDFB9030ADABDF417BDA60ABC+ACF48BCBCECFFCBFBCABCFCEACF483FCE72FCE24ABC

△△4818B+BAC18080DADBDABBACDAB+BC202019ABACOAOABOACABOOCABACOACBACABCACBE90BOC+E1802BAC+90BACBAC3620PFPGAMAPFCBBPCPPEPGPE7.5

SS+2BC514+14△△ACPABPAB35621ABACDADBC240BAD5022ABCADADB+CABC2ADBACDABCADAD

DABAB23ACB90CAB+BB3030230ADDBECACB90ADDEDEDB24CCABBCD，DAEBABADBDDAEDAEB390B30ABB25eq\o\ac(△,Rt)C90

222222222222ABABDBECExeq\o\ac(△,Rt)ACEC90CE+AC

AEx+6x，

26DEABCDCDEeq\o\ac(△,Rt)eq\o\ac(△,Rt)DEBeq\o\ac(△,Rt)DCFeq\o\ac(△,Rt)CF2AFeq\o\ac(△,Rt)DCFeq\o\ac(△