求教人教版数学初二上册第129页习题第八题，习题解答及其过程！跪求！谢谢
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1. \uff08\u6e56\u5317\u5b9c\u660c\uff09 \u5982\u56fe\u6240\u793a\uff0cBC\uff1d6\uff0cE\u3001F\u5206\u522b\u662f\u7ebf\u6bb5
AB\u548c\u7ebf\u6bb5AC\u7684\u4e2d\u70b9\uff0c\u90a3\u4e48\u7ebf\u6bb5EF\u7684\u957f\u662f\uff08 \uff09\uff0e
\uff08A\uff096 \uff08B\uff095 \uff08C\uff094.5 \uff08D\uff093
2\uff082005\u5e74\u82cf\u5dde\uff09\u5982\u56fe\uff0c\u5df2\u77e5\u7b49\u8170\u68af\u5f62ABCD\u7684\u4e2d\u4f4d\u7ebf
EF\u7684\u957f\u4e3a6\uff0c\u8170AD\u7684\u957f\u4e3a5\uff0c\u5219\u8be5\u7b49\u8170\u68af\u5f62\u7684\u5468\u957f\u4e3a\uff08 \uff09
A\uff0e11 B\uff0e16 C\uff0e17 D\uff0e22
3.\uff082004\u5e74\u6cb3\u5317\uff09\u5982\u56fe\uff0c\u5728\u68af\u5f62ABCD\u4e2d\uff0cAD//BC\uff0c\u5bf9\u89d2\u7ebfAC\u22a5BD\uff0c\u4e14AC=12\uff0cBD=9\uff0c\u5219\u6b64\u68af\u5f62\u7684 \u4e2d\u4f4d\u7ebf\u957f\u662f( )
A\uff0e B\uff0e
C\uff0e D\uff0e
4.\uff08\u7389\u6eaa\u5e022005\uff09\u5982\u56fe\uff0c\u5df2\u77e5EF\u662f\u68af\u5f62ABCD\u7684\u4e2d\u4f4d\u7ebf\uff0c
\u82e5AB\uff1d8\uff0cBC\uff1d6\uff0c CD\uff1d2\uff0c\u2220B\u7684\u5e73\u5206\u7ebf\u4ea4EF\u4e8eG\uff0c
\u5219FG\u7684\u957f\u662f\uff08 \uff09
A\uff0e1 B\uff0e1.5 C\uff0e2 D\uff0e2.5
5.\uff082005\u6cf0\u5dde\uff09\u5982\u56fe\uff0c\u68af\u5f62ABCD\u4e2d\uff0cAD//BC\uff0cBD\u4e3a\u5bf9\u89d2\u7ebf\uff0c
\u4e2d\u4f4d\u7ebfEF\u4ea4BD\u4e8eO\u70b9\uff0c\u82e5FO\uff0dEO=3\uff0c\u5219BC\uff0dAD\u7b49\u4e8e ( )
A\uff0e4 B\uff0e6 C\uff0e8 D\uff0e10
6.\u5982\u56fe\uff0c\u68af\u5f62ABCD\u4e2d\uff0cAD\u2016BC\uff0cE\u3001F\u5206\u522b\u662fAB\u3001DC\u7684\u4e2d\u70b9\uff0cEF\u4ea4BD\u4e0eG\uff0c\u4ea4AC\u4e0eH\uff0c\u82e5AD=2\uff0cBC=5\uff0c\u5219GH=___________
7.\uff08\u5e7f\u5dde\uff09\u5982\u56fe\uff0c\u5728\u6b63\u65b9\u5f62ABCD\u4e2d\uff0cAO\u22a5BD\uff0cOE\u3001FG\u3001HL
\u90fd\u5782\u76f4\u4e8eAD\uff0cEF GH IJ\u90fd\u5782\u76f4\u4e8eAO\uff0c
\u82e5\u5df2\u77e5S\u25b3AIJ=1,\u5219S\u6b63\u65b9\u5f62ABCD= .
8.\uff08\u4e0a\u6d7705)\u5728\u25b3ABC\u4e2d\uff0c\u70b9D\u3001E\u5206\u522b\u5728\u8fb9AB\u548cAC\u4e0a\uff0c
\u4e14DE\u2016BC\uff0c\u5982\u679cAD=2\uff0cDB=4\uff0cAE=3\uff0c\u90a3\u4e48EC= .
9.\uff08\u9ed1\u9f99\u6c5f05\uff09\u5728\u76f8\u540c\u65f6\u523b\u7684\u7269\u9ad8\u4e0e\u5f71\u957f\u6210\u6bd4\u4f8b\uff0c\u5c0f\u660e\u7684\u8eab\u9ad8\u4e3a1.5\u7c73\uff0c\u5728\u5730\u9762\u4e0a\u7684\u5f71\u957f\u4e3a2\u7c73\uff0c\u540c\u65f6\u4e00\u53e4\u5854\u5728\u5730\u9762\u4e0a\u7684\u5f71\u957f\u4e3a40\u7c73\uff0c\u5219\u53e4\u5854\u9ad8\u4e3a\uff08 \uff09.
A.60\u7c73 B.40\u7c73 C.30\u7c73 D.25\u7c73
10.\uff08\u53a6\u95e82005\uff09\u5df2\u77e5\uff1a\u5982\u56fe\uff0c\u5728\u25b3ABC\u4e2d\uff0c\u2220ADE\uff1d\u2220C\uff0c\u5219\u4e0b\u5217\u7b49\u5f0f\u6210\u7acb\u7684\u662f\uff08 \uff09
A. ADAB\uff1dAEAC B. AEBC\uff1dADBD
C. DEBC\uff1dAEAB D. DEBC\uff1dADAB
11.\uff08\u8fde\u4e91\u6e2f\u5e022005\uff09\u5982\u679c\u4e09\u89d2\u5f62\u7684\u6bcf\u6761\u8fb9\u90fd\u6269\u5927\u4e3a\u539f\u6765\u76845\u500d\uff0c\u90a3\u4e48\u4e09\u89d2\u5f62\u7684\u6bcf\u4e2a\u89d2\uff08 \uff09
\uff08A\uff09\u90fd\u6269\u5927\u4e3a\u539f\u6765\u76845\u500d \uff08B\uff09\u90fd\u6269\u5927\u4e3a\u539f\u6765\u768410\u500d
\uff08C\uff09\u90fd\u6269\u5927\u4e3a\u539f\u6765\u768425\u500d \uff08D\uff09\u90fd\u4e0e\u539f\u6765\u76f8\u7b49
12.(\u6d77\u6dc005)\u5982\u56fe\uff0c\u68af\u5f62ABCD\u4e2d\uff0cAB\u2016DC\uff0c\u2220B=90\u00b0\uff0c
E\u4e3aBC\u4e0a\u4e00\u70b9\uff0c\u4e14AE\u22a5ED.\u82e5BC=12\uff0cDC=7\uff0c
BE:EC=1:2\uff0c\u6c42AB\u7684\u957f.
13. \u5728\u5e73\u9762\u76f4\u89d2\u5750\u6807\u7cfb\u4e2d\uff0c\u5df2\u77e5\u70b9A\uff08-3\uff0c0\uff09\uff0cB\uff080\uff0c-4\uff09\uff0cC\uff080\uff0c1\uff09\u8fc7\u70b9C\u4f5c\u76f4\u7ebf \u4ea4 \u8f74\u4e8e\u70b9D\uff0c\u4f7f\u5f97\u4ee5\u70b9D\u3001C\u3001O\u4e3a\u9876\u70b9\u7684\u4e09\u89d2\u5f62\u4e0e\u25b3AOB\u76f8\u4f3c\uff0c\u8fd9\u6837\u7684\u76f4\u7ebf\u4e00\u5171\u53ef\u4ee5\u505a\u51fa\uff08 \uff09
A.\u4e00\u6761 B.\u4e24\u6761 C.\u56db\u6761 D.\u516b\u6761
14\uff0e\u5982\u56fe\uff0c\u77e9\u5f62ABCD\u7684\u957fAD = 9cm\uff0c\u5bbdAB = 4cm\uff0cAE = 2cm\uff0c\u7ebf\u6bb5MN = 3 cm\uff0c\u7ebf\u6bb5MN\u7684\u4e24\u7aef\u5728CB\u3001CD\u4e0a\u6ed1\u52a8\uff0c\u5f53\u22bfADE\u4e0e\u4ee5M\u3001N\u3001C\u4e3a\u9876\u70b9\u7684\u4e09\u89d2\u5f62\u76f8\u4f3c\u65f6\uff0cCM\u7684\u957f\u4e3a cm. 15\uff08\u6dc4\u535a\u5e022004\uff09 \u5982\u56fe\uff0c\u22201\uff1d\u22202\uff1d\u22203\uff0c
\u5219\u56fe\u4e2d\u76f8\u4f3c\u4e09\u89d2\u5f62\u5171\u6709\uff08 \uff09\uff08A\uff091\u5bf9\uff08B\uff092\u5bf9\uff08C\uff093\u5bf9 \uff08D\uff094\u5bf9
16.\u9488\u5b54\u6210\u50cf\u95ee\u9898\uff09\u6839\u636e\u53f3\u56fe\u4e2d\u5c3a\u5bf8
\uff08 \u2016 \uff09\u90a3\u4e48\u7269\u50cf\u957f \uff08 \u7684\u957f\uff09
\u4e0e\u7269\u957f \uff08 \u7684\u957f\uff09\u4e4b\u95f4\u51fd\u6570\u5173\u7cfb\u7684\u56fe\u8c61
\u5927\u81f4\u662f\uff08 \uff09
17.\uff082005\u5e74\u5317\u4eac\uff09\u5982\u56fe\uff0c\u5728\u5e73\u884c\u56db\u8fb9\u5f62ABCD\u4e2d\uff0cE\u662fAD\u4e0a\u4e00\u70b9\uff0c\u8fde\u7ed3CE\u5e76\u5ef6\u957f\u4ea4BA\u7684\u5ef6\u957f\u7ebf\u4e8e\u70b9F\uff0c\u5219\u4e0b\u5217\u7ed3\u8bba\u4e2d\u9519\u8bef\u7684\u662f\uff08 \uff09
A. \u2220AEF\uff1d\u2220DEC B. FA:CD\uff1dAE:BC C. FA:AB\uff1dFE:EC D. AB\uff1dDC
18.\uff082005\u5e74\u5e38\u5fb7\uff09\u5982\u56fe\uff0cDE\u662f\u0394ABC\u7684\u4e2d\u4f4d\u7ebf\uff0c
\u5219\u0394ADE\u4e0e\u0394ABC\u7684\u9762\u79ef\u4e4b\u6bd4\u662f\uff08 \uff09 A\uff0e1:1 B\uff0e1:2 C\uff0e1:3 D\uff0e1:4
19.\uff082004\u5e74\u9f99\u5ca9\uff09\u628a\u4e00\u5757\u5468\u957f\u4e3a20cm\u7684\u4e09\u89d2\u5f62\u94c1\u7247\u88c1\u6210\u56db\u5757\u5f62\u72b6\u3001\u5927\u5c0f\u5b8c\u5168
\u76f8\u540c\u7684\u5c0f\u4e09\u89d2\u5f62\u94c1\u7247\uff08\u5982\u56fe\u793a\uff09\uff0c\u5219\u6bcf\u5757\u5c0f\u4e09\u89d2\u5f62\u94c1\u7247\u7684\u5468
\u957f\u4e3a cm.
20..\u5df2\u77e5: \u5982\u56fe,AO\u662f\u25b3ABC\u7684\u2220A\u7684\u5e73\u5206\u7ebf\uff0cBD\u22a5AO,
\u4ea4AO\u7684\u5ef6\u957f\u7ebf\u4e8eD,E\u662fBC\u7684\u4e2d\u70b9\uff0c\u6c42\u8bc1\uff1aDE= (AB-AC).
21. \u5df2\u77e5:\u5982\u56fe,E\u3001F\u628a\u56db\u8fb9\u5f62ABCD\u7684\u5bf9\u89d2\u7ebfBD
\u4e09\u7b49\u5206, CE\uff0cCF\u7684\u5ef6\u957f\u7ebf\u5206\u522b\u5e73\u5206AB,AD.
\u6c42\u8bc1: \u56db\u8fb9\u5f62ABCD\u662f\u5e73\u884c\u56db\u8fb9\u5f62.
22.\u6c42\u8bc1: \u56db\u8fb9\u5f62\u7684\u5bf9\u89d2\u7ebf\u7684\u4e2d\u70b9\u8fde\u7ebf\u4e0e\u5bf9\u8fb9\u4e2d\u70b9\u7684\u8fde\u7ebf\u4e92\u76f8\u5e73\u5206
23\uff0e\u5982\u56fe\uff0c\u5728\u56db\u8fb9\u5f62ABCD\u4e2d\uff0cAB=CD,E\u3001F\u3001\u5206\u522b\u662fAD\u3001BC\u7684\u4e2d\u70b9\uff0c
\u5ef6\u957fBA\u3001FE\u4ea4\u4e8eG\uff0c\u5ef6\u957fCD\u3001FE\u4ea4\u4e8eH.\uff0c\u6c42\u8bc1\uff1a\u22201=\u22202
24.\u5df2\u77e5:\u5982\u56fe,\u68af\u5f62ABCD,AB\u2016DC,AB+CD=8,AB:CD=7:3,
E,F\u5206\u522b\u662fAC\u3001BD\u7684\u4e2d\u70b9, \u6c42EF\u7684\u957f
25.\u5982\u56fe, \u25b3ABC\u4e2d,P\u4e3aAB\u7684\u4e2d\u70b9,D\u4e3aAP\u7684\u4e2d\u70b9,
E\u3001Q\u4e3aAC, CD\u7684\u4e2d\u70b9,F\u4e3aPQ\u7684\u4e2d\u70b9,EF\u4ea4AB\u4e8eG,
\u6c42\u8bc1:DG=BG.
26.\uff082005\u5e7f\u4e1c\u7701\uff09\u5982\u56fe\uff0c\u7b49\u8170\u68af\u5f62ABCD\u4e2d\uff0cAD\u2016BC\uff0cM\u3001N\u5206\u522b
\u662fAD\u3001BC\u7684\u4e2d\u70b9\uff0cE\u3001F\u5206\u522b\u662fBM\u3001CM\u7684\u4e2d\u70b9\u3002
\uff081\uff09\u6c42\u8bc1\uff1a\u56db\u8fb9\u5f62MENF\u662f\u83f1\u5f62\uff1b
\uff082\uff09\u82e5\u56db\u8fb9\u5f62MENF\u662f\u6b63\u65b9\u5f62\uff0c\u8bf7\u63a2\u7d22\u7b49\u8170\u68af\u5f62ABCD
\u7684\u9ad8\u548c\u5e95\u8fb9BC\u7684\u6570\u91cf\u5173\u7cfb\uff0c\u5e76\u8bc1\u660e\u4f60\u7684\u7ed3\u8bba\u3002
27. \uff08\u56db\u5ddd\u8d44\u9633\uff09 \u5982\u56fe5\uff0c\u5df2\u77e5\u70b9M\u3001N\u5206\u522b\u662f\u25b3ABC\u7684\u8fb9BC\u3001
AC\u7684\u4e2d\u70b9\uff0c\u70b9P\u662f\u70b9A\u5173\u4e8e\u70b9M\u7684\u5bf9\u79f0\u70b9\uff0c\u70b9Q\u662f\u70b9B\u5173\u4e8e\u70b9N\u7684\u5bf9\u79f0\u70b9\uff0c
\u6c42\u8bc1\uff1aP\u3001C\u3001Q\u4e09\u70b9\u5728\u540c\u4e00\u6761\u76f4\u7ebf\u4e0a.
28.\u5982\u56fe\uff0c\u56db\u8fb9\u5f62ABCD\u4e2d\uff0cAC=6\uff0cBD=8\u4e14AC\u22a5BD\u987a\u6b21\u8fde\u63a5\u56db\u8fb9\u5f62ABCD\u5404\u8fb9\u4e2d\u70b9\uff0c\u5f97\u5230\u56db\u8fb9\u5f62A1B1C1D1\uff1b\u518d\u987a\u6b21\u8fde\u63a5\u56db\u8fb9\u5f62A1B1C1D1\u5404\u8fb9\u4e2d\u70b9\uff0c\u5f97\u5230\u56db\u8fb9\u5f62A2B2C2D2\u2026\u2026\u5982\u6b64\u8fdb\u884c\u4e0b\u53bb\u5f97\u5230\u56db\u8fb9\u5f62AnBnCnDn .
\uff081\uff09\u8bc1\u660e\uff1a\u56db\u8fb9\u5f62A1B1C1D1\u662f\u77e9\u5f62\uff1b
\uff082\uff09\u5199\u51fa\u56db\u8fb9\u5f62A1B1C1D1\u548c\u56db\u8fb9\u5f62A2B2C2D2\u7684\u9762\u79ef\uff1b
\uff083\uff09\u5199\u51fa\u56db\u8fb9\u5f62AnBnCnDn\u7684\u9762\u79ef\uff1b
\uff084\uff09\u6c42\u56db\u8fb9\u5f62A5B5C5D5\u7684\u5468\u957f.
29\uff0e\u5df2\u77e5\uff1a\u5982\u56fe\uff0cAD\u5e73\u5206\u2220BAC,DE\u2016CA,AB=15,
AC=12, \u6c42DE\u7684\u957f.
30.\u5df2\u77e5\uff1a\u5982\u56fe\uff0cD\u5728\u25b3ABC\u7684BC\u8fb9\u4e0a\uff0cDF\u2016BA,
DE\u2016CA, DE\u2236DF=1\u22362,AB=6,AC=4,
\u6c42DE\u7684\u957f.
31.\u5df2\u77e5\uff1a\u5982\u56fe\uff0c\u25b3ABC\u4e2d\uff0cAD\u5e73\u5206\u2220BAC,AB=5,
AC=3,BC=5.6, \u6c42BD\u548cDC\u7684\u957f.
32.\u5df2\u77e5\uff1a\u5982\u56fe\uff0c ABCD,E\u662fCD\u5ef6\u957f\u7ebf\u4e0a\u4e00\u70b9\uff0cBE
\u4ea4AD\u4e8eF,AB=12,DE=3,BE=30, \u6c42BF\u548cEF\u7684\u957f.
33. \u5df2\u77e5\uff1a\u5982\u56fe\uff0c ABCD, E\u4e3aBC\u7684\u4e2d\u70b9,BF= AB,EF\u4e0e
\u5bf9\u89d2\u7ebfBD\u76f8\u4ea4\u4e8eG,\u82e5BD=20, \u6c42BG\u7684\u957f.
34.\u5df2\u77e5\uff1a\u5982\u56fe\uff0c\u25b3ABC\u4e2d\uff0c\u76f4\u7ebfDE\u4ea4AB\u3001AC\u3001BC\u4e8eD\u3001E\u3001
F\uff0cAE=BF
\u6c42\u8bc1\uff1a
35.\u5df2\u77e5\uff1a\u5982\u56fe\uff0cAD\u4e3a\u25b3ABC\u7684\u4e2d\u7ebf\uff0cE\u4e3aAD\u4e0a\u4e00\u70b9\uff0c
CE\u5ef6\u957f\u7ebf\u4ea4AB\u4e8eF,
\u6c42\u8bc1\uff1a
36.\u5df2\u77e5\uff1a\u5982\u56fe\uff0cAD\u4e3a\u25b3ABC\u7684\u4e2d\u7ebf\uff0cM\u4e3aAD\u4e2d\u70b9\uff0c
BM\u5ef6\u957f\u7ebf\u4ea4AC\u4e8eN,
\u6c42\u8bc1\uff1aAN\u2236CN=1\u22362
37.\u5df2\u77e5\uff1a\u5982\u56fe\uff0cM\u3001N\u5206\u522b\u4e3aAB\u3001CD\u4e2d\u70b9\uff0c
AD\u3001BC\u5206\u522b\u4ea4MN\u4e8eE\u3001F
\u6c42\u8bc1\uff1aED\u2236EA=FC\u2236FB
38.\u5df2\u77e5\uff1a\u5982\u56fe\uff0cAD\u22a5BC\u4e8eD\uff0cE\u662fAC\u4e2d\u70b9\uff0c\u8fde\u7ed3DE\u4ea4BA\u4e8eF
\u6c42\u8bc1\uff1a
39.\u5df2\u77e5\uff1a\u5982\u56fe\uff0c ABCD,AC\u3001BD\u4ea4\u4e8eO,OF\u4ea4BC\u4e8eE,
\u4ea4AB\u5ef6\u957f\u7ebf\u4e8eF,
\u6c42\u8bc1\uff1aBE(AB+2BF)=BC•BF
40\uff0e\u5df2\u77e5\uff1a\u5982\u56fe\uff0cD,E\u662fAB\u3001AC\u8fb9\u4e0a\u7684\u70b9\uff0c\u8fde\u7ed3DE\u5e76\u5ef6\u957f\u4ea4BC\u5ef6\u957f\u7ebf\u4e8eF, \u4e14AD=AE,
\u6c42\u8bc1\uff1a
41\uff0e\uff08\u672c\u98986\u5206\uff09\u5982\u56fe\uff0c\u76f4\u89d2\u4e09\u89d2\u5f62ABC\u4e2d\uff0c\u2220C = 90\u00b0\uff0cAC = 8\uff0cBC = 6\uff0c\u4e14AB2=AC2+BC2\u5c06AB
\u5341\u7b49\u5206\uff0cP1\u3001P2\u3001\u2026\u2026\u3001P9\u4e3a\u7b49\u5206\u70b9\uff0c\u8fdeCP1\u3001CP2\u3001\u2026\u2026\u3001CP9\uff0c\u8bf7\u4f60\u5728\u56fe\u4e2d\u627e\u51fa\u4e00\u5bf9\u76f8\u4f3c\u4e09\u89d2\u5f62\uff0c
\u5e76\u8bf4\u660e\u5b83\u4eec\u76f8\u4f3c\u7684\u7406\u7531\u3002
42.\uff082005\u5e74\u65e0\u9521\uff09\u5df2\u77e5\u56fe1\u548c\u56fe2\u4e2d\u7684\u6bcf\u4e2a\u5c0f\u6b63\u65b9\u5f62\u7684\u8fb9\u957f\u90fd\u662f1\u4e2a\u5355\u4f4d.
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\uff082\uff09\u5728\u56fe2\u4e2d\u753b\u51fa\u4e00\u4e2a\u4e0e\u683c\u70b9\u25b3DEF\u76f8\u4f3c\u4f46\u76f8\u4f3c\u6bd4\u4e0d\u7b49\u4e8e1\u7684\u683c\u70b9\u4e09\u89d2\u5f62.
43.\u5982\u56fe\uff0c\u5728\u25b3ABC\u4e2d\uff0c\u2220C=90\u00b0\uff0cAC=6\uff0cBC=8\uff0cM\u662fBC\u7684\u4e2d\u70b9\uff0cP\u4e3aAB\u4e0a\u7684\u4e00\u4e2a\u52a8\u70b9\uff0c\uff08\u53ef\u4ee5\u4e0eA\u3001B\u91cd\u5408\uff09\uff0c\u5e76\u4f5c\u2220MPD=90\u00b0\uff0cPD\u4ea4BC\uff08\u6216BC\u7684\u5ef6\u957f\u7ebf\uff09\u4e8e\u70b9D.
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\u8fd8\u6709http://www.jxjyzy.com/ResourceHtml/727934.html
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\u5728\u201c\u6559\u5e08\u7528\u4e66\u201d\u4e2d\u53ef\u4ee5\u627e\u5230\u7b54\u6848\u3002
解：根据题意得y=2.4 （x<3）
2.4+（x-3）=x-0.6 (x>=3)
（分段函数，大括号不好表示，能明白吧？）
当y=10时，10=x-0.6
x=9.4，x取整为10
解得x=10
（要自变量取值的实际意义）
希望对你有所帮助！不明白的地方可以追问或私聊我！
y=2.4 （x<3）
2.4+（x-3）=x-0.6 (x>=3)
你买一本教材全解里面有每页书的答案
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