1、 1 13 1 ABCD AE BC E B ABC BAE A B C D 2 Rt ABC ABC A B C B A B C D 3 ABC ABC A AB A B C D 4 E F ABCD AB BC BE=CF CE DF DCF O CBE A B C D 2 5 Rt ABC Rt EDF D AB DE AC P DF C EDF D AC M BC N A B C D 6 ABCD AB=4 BC=3 l B 2015 A A B C D 7 1 ABCD A AB1C1D1 B1C1 CD O AB1OD A B C D 1 8 A B C D 9 A. B C D
2、3 10 ABCD A AC D CD E AB=3 AEC A 3 B 1.5 C 2 D 11 ODC OAB O D AB AOC DOB A B C D 12 OABC O ODEF AF OFA A B C D 13 D AC DM DN E F DEF D DE=DF BDN A B C D 14 14 ABC AC=BC ACB= O AB BO OA=1 BOC C AQC AQC= 4 15 Rt ABC AC=5cm BC=12cm ABC B BDE DC AB F ACF BDF cm 16 Rt ABC AC=BC=1 A AB x ABC x A x A x 17
3、Rt ABC AB=BC= ABC C MNC BM BM 18 O ABCD A B 1 1 1 1 ABCD O ABCD 5 19 ABC A AED AB=3 BE= 20 ABC D AD=5 BD=6 CD=4 ABD A AB AC D E CDE 21 ABCD B BEFG EF AD H DA GF K ABCD AK= 22 Rt ABC AC=6 BC=4 ABC C DEC F DE AF AF= 6 23 ABCD AB=4 AD=10 BD DBC BE DC E BCE B BCE AD F G BFD DG 24 ABC AC=BC B ABC AC 25 4
4、 4 1 AOB O COD 26 ABC A ADE BAD= 27 OAB O A B 1= 7 3 28 ABC CA=CB E F CA CB ECF C MCN AM BN 1 AM=BN 2 MA CN 29 ABC AB=AC=1 AEF ABC A BE CF D 1 BE=CF 2 ACDE BD 30 BAD BEC B AB BC BE=CE DE 1 BDE BCE 2 ABED 8 2016 13 1 ABCD AE BC E B ABC BAE A B C D ABCD AE BC E BAE + C 2 Rt ABC ABC A B C B A B C D 9 +
5、 + B= B C 3 ABC ABC A AB A B C D AB ABC A 2 2 C 4 E F ABCD AB BC BE=CF CE DF DCF O CBE A B C D ABCD O 10 OD=OC OD OC D C OC OD DOC DCF O CBE D 5 Rt ABC Rt EDF D AB DE AC P DF C EDF D AC M BC N A B C D D AB CD=AD=DB ACD= BCD= MPD= NCD EDF D PDM= PDM CDN = Rt PCD tan 11 C 6 ABCD AB=4 BC=3 l B 2015 A A
6、 B C D A 0 A A + 2015 4=503 3 A D 7 1 ABCD A AB1C1D1 B1C1 CD O AB1OD A B C D 1 AC1 12 AB1C1D1 C1AB1= AC1B1 1 ABCD A AB1C1D1 B1 DAB1 AC1 D A D C1 ABCD 1 AB1C1D1 1 Rt C1D1A AC1= = DC1= 1 AC1B1 C1DO=90 C1 DC1O DC1=OD= 1 S ADO= AB1OD =2 = 1 D 8 A B C D A B C 13 D B 9 A. B C D D 10 ABCD A AC D CD E AB=3
7、AEC A 3 B 1.5 C 2 D AC D AD= AC Rt ACD EAC= AE=CE Rt ADE AE=EC=x DE=DC EC=AB EC=3 x AD= 3= x 2 = 3 x 2 + 2 14 x=2 EC=2 S = D 11 ODC OAB O D AB AOC DOB A B C D C 12 OABC O ODEF AF OFA A B C D OABC O ODEF + OA=OF OFA= C 13 D AC DM DN E F DEF D DE=DF BDN 15 A B C D DE=DF DFC= EDF BDN= DFC+ + C 14 14 ABC AC=BC O AB BO OA=1 BOC C AQC AQC= OQ AC=BC BAC= AQC BOC AQ=BO CQ=CO QAC= ACQ= BCO OAQ= BAC+ OCQ= OCA+ ACQ= OCA+ BO OA=1 BO=1 OA= 16 AQ=1 tan AQO= = 15 Rt ABC AC=5cm BC=12cm ABC B BDE DC AB F ACF BDF 42 cm ABC B BDE ABC BDE CBD=
