九年級數(shù)學圓的知識點總結(jié)大全

1、amende d Decree No. 344 2011.12.1 the State Council promulgated by DecreeNo. 591, 9 People's Republic of Chi na regulations on r oad transport 2004.07.012004.01.13 10 safety production licenseOrdi nance, pr omulgatedby Decree No. 406 of the State Council promulgated by Decreeof the State Council

2、, No. 397 112007.06.01productionsafety acci dent re porting, investigation and handli ng of Ordinancepromulgated by De cree No. 493, 12 ofthe State Council regulations on special equipment safety supervision 2009.05.01 amendedDecre e No. 373 State Council DecreeNo. 549, 13 insura nce regulations reg

3、arding industrial injurie s 2011.01.01 amendment, promulgatedby Decre e No. 586 of the State Council promulgated by Decree No. 375, 14 administration of precursor chemicalsOrdi nance 2005.11.01 State Council DecreeNo. 445, 15 workplaces where toxic substances areuse d to labour protection 2002.05.12

4、 the State Council promulgated by Decree No. 352, 16 women workers . 4.6 review and revision 4.6.1production technology secti on Office organized relevantdepartme nts units once a year to review the documentation issued by, not suitablmaterial changes on or after an accident, and biotech branch and

5、that the workshopshoul d be timely to various reg ulations and safety rules be revised to ensure suitability and effectiveness. 4.6.3 revision of the file change approval form should be filled in, i ndi cating the causes andcha nges, a ppr oved by the Deputy incharge of security, General Manager of

6、revision. 4.6.4 anew revised safety regulations and safety rules shouldbe released to the post in a timely manner to ensure rules a ndsafety regulations of each post is the latest file, recover theoriginal documentunifie d void. 5. related records 5.1 list of applicable laws, regulations a nd standa

7、rdsof the inventory listingnumber carbon industry laws and regulations legal regulations and other requirementscame into for ce date enacte d se ctor update record 1/standardnumber Pe ople's Republicof China 2, Chairmanof the national people's Congress made the 70th producti on safety law 20

8、02.11.1 Peopl e's Republicof China La w of occupational diseaseprevention 2002.05.01labor law 2008.1.1, Chairmanof the nationalpeople's Congress Standing Committee, 65th 5People's Republic of China on road traffic safety law 2011.5.1, Chairmanof the national people's Congress made th

9、e 47th, 6People's Republic of China Trade Union law 2001.10.27 7,Chairman of the national people' s Congress made the 62nd People's Republic of China emergency response law 2007.11.1,Chairman of the nationa l pe ople's Co ngress, the 69t h 8 Hazardous chemical safety management regul

10、ation amende d Decree No. 344 2011.12.1 the State Council promulgated by DecreeNo. 591, 9People's Republi c of China regulations on road transport 2004.07.012004.01.13 10 safety production license Ordinance,第四章：圓一、知識回顧圓的周長 ： C=2 r 或 C=d、圓的面積 ：S=r 2圓環(huán)面積計算方法： S= R2- r 2或 S=（ R2-r 2）(R 是大圓半徑， r 是小圓

11、半徑）二、知識要點一、圓的概念集合形式的概念：231 、 圓可以看作是到定點的距離等于定長的點的集合；、圓的外部：可以看作是到定點的距離大于定長的點的集合；、圓的內(nèi)部：可以看作是到定點的距離小于定長的點的集合軌跡形式的概念：1、圓：到定點的距離等于定長的點的軌跡就是以定點為圓心，定長為半徑的圓；固定的端點 O為圓心。連接圓上任意兩點的線段叫做弦，經(jīng)過圓心的弦叫直徑。 圓上任意兩點之間的部分叫做圓弧，簡稱弧。2、垂直平分線：到線段兩端距離相等的點的軌跡是這條線段的垂直平分線；3、角的平分線：到角兩邊距離相等的點的軌跡是這個角的平分線；4、到直線的距離相等的點的軌跡是：平行于這條直線且到這條直線的

12、距離等于定長的兩條直線；5、到兩條平行線距離相等的點的軌跡是：平行于這兩條平行線且到兩條直線距離都相等的一條直線。二、點與圓的位置關系1、點在圓內(nèi)dr點C在圓內(nèi)；Ad2、點在圓上dr點 B 在圓上；rOB3、點在圓外dr點 A 在圓外；dC三、直線與圓的位置關系1、直線與圓相離dr無交點；2、直線與圓相切dr有一個交點；3、直線與圓相交dr有兩個交點；rd=rrdd四、圓與圓的位置關系promulgatedby De cree No. 406 of the State Councilpromulgatedby Decreeof the State Council,No. 397 11 2007

13、.06.01 production safety accident reporting, investigation a ndhandlingof Ordi na nce promulgated by De cree No.493,12 of the State Council regulations on special equipment safety supervision 2009.05.01 amende d Decree No. 373 State Council DecreeNo. 549, 13 insurance r egulations regarding i ndustr

14、ial injuries 2011.01.01 amendment,promulgated by Decree No. 586 of the State Councilpromulgated by DecreeNo. 375,14 admi nistration of precursor chemicals Ordinance2005.11.01 StateCouncil De cree No. 445, 15 workplace s where toxicsubstances areused to labour protection 2002.05.12 the State Councilp

15、romulgatedby De cree No. 352, 16 women workers . 4.6. review and revise 4.6.1production te chnol ogy section Officeonce every year and organize relev ant departments to review unit on the issuing of system files, not suitable documents be revised i n a timely manner.revisionof the filecha nge approv

16、al form shouldbe filled in, i ndi cating the cause s and changes, approved by the De puty in charge of security, General Manager of revision. 4.6.4 a new revised safety regulations and safety rulesshould be released to the post in atimely manner to ensure rules a nd safety regulationsof each post is

17、 the latest file, recover t he origi nal documentunified void. 5. related records5.1 list of applica ble laws, regulations and standards of the inventory listing number carbon industry laws and regulations legal regulations and other requirements came into forcedate ena cted se ctorupdate record 1 /

18、standardnumberPeople's Republicof Chi na 2,Chairman of thenationalpeople's Congress made the 70thproductionsafety law 2002.11.1 People's Republicof Chi naLaw of occupationaldisea se prevention 2002.05.01NPC3, or der of the Presi dentof the 60th People'Congre ss made the 47th, 6 Peopl

19、e's Republic of China Trade Union law 2001.10.27 7,Chairman of the national people'sCongress made the 62nd People's Republic of China emergency response law 2007.11.1, Chairmanof the nationalpeople'sCongress, the 69th8Hazardous chemical safety management regulation amended DecreeNo.

20、344 2011.12.1 the State Councilpromulgated by Decree No. 591, 9 People' s Republic of China regulationson road transport 2004.07.01 2004.01.13 10safety production license Ordinance, promulgated by Decree No. 406 of the State CouncilpromulgatedbyDecree of the State Council, No. 397 11 2007.06.01

21、production safety accident re porti ng, investigation and handling of Or dinance promulgated by Decree外離（圖 1）無交點dRr ；外切（圖 2）有一個交點dRr ；相交（圖 3）有兩個交點Rrd R r ；內(nèi)切（圖 4）有一個交點dRr ；內(nèi)含（圖 5）無交點dRr ；dddRrRrRr圖 1圖 2圖 3ddrRrR圖4圖5五、垂徑定理垂徑定理：垂直于弦的直徑平分弦且平分弦所對的弧。推論 1：（ 1）平分弦（不是直徑）的直徑垂直于弦，并且平分弦所對的兩條??；（2）弦的垂直平分線經(jīng)過圓心，并且

22、平分弦所對的兩條弧；（3）平分弦所對的一條弧的直徑，垂直平分弦，并且平分弦所對的另一條弧以上共 4 個定理，簡稱 2 推 3 定理：此定理中共5 個結(jié)論中，只要知道其中2 個即可推出其它 3 個結(jié)論，即：AB是直徑 ABCD CE DE 弧BC弧 BD 弧AC弧 AD中任意 2 個條件推出其他3 個結(jié)論。A推論 2：圓的兩條平行弦所夾的弧相等。即：在 O 中， AB CDCDOO弧 AC弧 BDABEDCB六、圓心角定理頂點到圓心的角，叫圓心角。圓心角定理：同圓或等圓中，相等的圓心角所對的弦相等，所對的弧相等，弦心距相等。此定理也稱 1 推 3 定理，即上述四個結(jié)論中，amende d Dec

23、ree No. 344 2011.12.1 the State Council promulgated by DecreeNo. 591, 9 People's Republic of Chi na regulations on r oad transport 2004.07.012004.01.13 10 safety production licenseOrdinance, promulgatedby Decree No. 406 of the State Council promulgated by Decreeof the State Council, No. 397 1120

24、07.06.01productionsafety acci dent re porting, investigation and handli ng of Ordinancepromulgated by De cree No. 493, 12 of the State Council regulations on special equipment safety supervision 2009.05.01 amendedDecre e No. 373 State Council DecreeNo. 549, 13 insura nce regulations regarding indust

25、rial injurie s 2011.01.01 amendment, promulgatedby Decree No. 586 of the State Council promulgated by Decree No. 375, 14 administration of precursor chemicalsOrdi nance 2005.11.01 State Council DecreeNo. 445, 15 workplaces where toxic substances areuse d to labour protection 2002.05.12 the State Cou

26、ncil promulgated by Decree No. 352, 16 women workers . 4.6 review and revision 4.6.1production technology secti on Office organized relevantdepartme nts units once a year to reviematerial changes on or after an accident, and biotech branch and that the workshopshoul d be timely to various reg ulatio

27、ns and safety rules be revised to ensure suitability and effectiveness. 4.6.3 revision of the file change approval form should be filled in, i ndi cating the causes andcha nges, a ppr oved by the Deputy incharge of security, General Manager of revision. 4.6.4 anew revised safety regulations and safe

28、ty rules shouldbe released to the post in a timely manner to ensure rules a ndsafety regulations of each post is the latest file, recover theoriginal documentunifie d void. 5. related records 5.1 list of applicable laws, regulations a nd standardsof the inventory listingnumber carbon indust ry laws

29、and regulations legal regulations and other requirementscame into for ce date enacte d se ctor update record 1/standardnumber Pe ople's Republicof China 2, Chairmanof the national people's Congress made the 70th producti on safety law 2002.11.1 Peopl e's Republicof China La w of occupati

30、onal diseaseprevention 2002.05.01labor law 2008.1.1, Chairmanof the nationalpeople's Congress Standing Committee, 65th 5People's Republic of China on road traffic safety law 2011.5.1, Chairmanof the national people's Congress made the 47th, 6People's Republic of China Trade Union law

31、 2001.10.27 7,Chairman of the nati onal people' s Congress made the 62nd People's Republic of China emergency response law 2007.11.1,Chairman of the nationa l pe ople's Congress, t he 69t h 8 Hazardous chemical safety management regulation amende d Decree No. 344 2011.12.1 the State Coun

32、cil promulgated by DecreeNo. 591, 9People's Republi c of China regulations on road transport 2004.07.012004.01.13 10 safety production license Ordinance,只要知道其中的1 個相等，則可以推出其它的E3 個結(jié)論，即： AOBDOE ；AB DE；FOOC OF ； 弧BA弧 BDDACB七、圓周角定理頂點在圓上，并且兩邊都與圓相交的角，叫圓周角。1、圓周角定理：同弧所對的圓周角等于它所對的圓心的即： AOB 和 ACB 是弧 AB 所對的

33、圓心角和圓周角 AOB 2 ACB2、圓周角定理的推論：推論 1：同弧或等弧所對的圓周角相等；同圓或等圓中，的弧是等?。籆角的一半。BOADC相等的圓周角所對即：在 O 中，C 、D 都是所對的圓周角CDBOA推論 2：半圓或直徑所對的圓周角是直角；圓周角是直角所C對的弧是半圓，所對的弦是直徑。即：在 O 中， AB 是直徑或C90C90AB是直徑BAO推論 3：若三角形一邊上的中線等于這邊的一半，那么這個三C角形是直角三角形。即：在 ABC 中， OC OA OBBOA ABC 是直角三角形或C90注：此推論實是初二年級幾何中矩形的推論：在直角三角形中斜邊上的中線等于斜邊的一半的逆定理。八、

34、圓內(nèi)接四邊形圓的內(nèi)接四邊形定理：圓的內(nèi)接四邊形的對角互補，外角等于它的內(nèi)對角。promulgatedby Decre e No. 406of the State Council promulgated by Decreeof the State Council, No. 39711 2007.06.01 production safety accident reporting, investigation and handling ofOrdina nce prom ulgated by DecreeNo. 493, 12of the State Council regulations on

35、special equipment safety supervision2009.05.01 amended Decree No. 373 State Council Decree No. 549, 13 insurance regulations regarding industrial injuries 2011.01.01 amendment, promulgated byDecreeNo. 586 of the State Council promulgated by Decree No. 375, 14 administration of precursor chemicalsOrd

36、inance 2005.11.01 State Council Decree No. 445, 15 workplaces where toxicsubstances are used to labour protection 2002.05.12 the State Councilpromulgated by De cree No. 352, 16 women workers . 4.6. review and revise 4.6.1production te chnol ogy sectionOff ice once every year and orga nize relevant d

37、epartments to review uniton the issuing of system files,not suitabledocuments be revised in a timely manner. 4.6.2 processes, technology, material changesonor after an accident, and biotech branch a nd that the workshop should be timely to various regulations a nd safety rules be revised to ensure s

38、uitability and effectiveness. 4.6.3revisionof the file change approval form shouldbe filled in, indicating the cause s and cha nges, a ppr oved by the De puty in charge of securit y, Ge neral Manager of revision. 4.6.4 anew revised safety regulations and safety rules should be released t o the p ost

39、 in a timely manner to ensure rules and safety regulationsof eachpost is the latest file, recover theoriginaldocumentunified v oid.5. related re cords 5.1 listof applicable laws, regulations and standards of the inventory listing num ber car bon industry laws a nd regulations legal regulations and o

40、ther requirements came into force date enacted sector update recor d 1/sta ndardnum ber Pe ople's Republic of China 2, Chairman of thenational peopl e's Congress made the 70th production safety law 2002.11.1 People' s Republicof Chi na Law of occupationa l disea se prevention 2002.05.01

41、NPC 3,order of thePresi dent of the 60th Peopl e's Republic of China fire control lawof 2009.05.01 4, Chairman of thenational people' s Congress Standi ng Committee 6thPeople's Republic of China labor law2008.1.1,Chairman of the national people'sCongress made the 47th, 6 People's

42、 Republic of China Trade Union law 2001.10.27 7,Chairma n of the nationalpeople's Congress made the 62nd People's Republic of China emergency response law 2007.11.1, Chairmanof the nati onalpeople'sCongress, the 69th 8Hazardous chemical safety management regulation amended Decree No. 344

43、 2011.12.1 the State Councilpromulgate d by Decree No. 591, 9 People's Republic of China regulationson road transport 2004.07.01 2004.01.13 10safety production license Or dinance, promulgated by Decree No. 406 of the State Councilpromulgatedby Decree of the State Council, No. 397 11 2007.06.01 p

44、roduction safety accident re porting, investigation and handling of Or dinance promulgated by Decree 3即：在 O 中，DC四邊形 ABCD 是內(nèi)接四邊形CBAD180BD180DAECBAE九、切線的性質(zhì)與判定定理（1）切線的判定定理：過半徑外端且垂直于半徑的直線是切線；兩個條件：過半徑外端且垂直半徑，二者缺一不可即： MN OA 且 MN 過半徑 OA外端MN 是O的切線O（2）性質(zhì)定理：切線垂直于過切點的半徑 （如上圖）推論 1：過圓心垂直于切線的直線必過切MAN點。推論 2：過切點垂直于

45、切線的直線必過圓心。以上三個定理及推論也稱二推一定理：即：過圓心；過切點；垂直切線，三個條件中知道其中兩個條件就能推出最后一個。十、切線長定理切線長定理：從圓外一點引圓的兩條切線， 它們的切線長相等，這點和圓心的連線平分兩條切線的夾角。即： PA 、 PB 是的兩條切線 PA PBPO 平分BPABOPA十一、圓冪定理（1）相交弦定理 ：圓內(nèi)兩弦相交，交點分得的兩條線段的乘DBO積相等。P即：在 O 中，弦 AB 、 CD 相交于點 P ， PA PB PC PDCA（2）推論：如果弦與直徑垂直相交， 那么弦的一半是它分直徑段的比例中項。C所成的兩條線BOEADamende d Decree

46、No. 344 2011.12.1 the State Council promulgated by DecreeNo. 591, 9 People's Republic of Chi na regulations on r oad transport 2004.07.012004.01.13 10 safety production licenseOrdinance, promulgatedby Decree No. 406 of the State Council promulgated by Decreeof the State Council, No. 397 112007.0

47、6.01productionsafety acci dent re porting, investigation and handli ng of Ordinancepromulgated by De cree No. 493, 12 of the State Council regulations on special equipment safety supervision 2009.05.01 amendedDecre e No. 373 State Council DecreeNo. 549, 13 insura nce regulations regarding industrial

48、 injurie s 2011.01.01 amendment, promulgatedby Decree No. 586 of the State Council promulgated by Decree No. 375, 14 administration of precursor chemicalsOrdi nance 2005.11.01 State Council DecreeNo. 445, 15 workplaces where toxic substances areuse d to labour protection 2002.05.12 the State Council

49、 promulgated by Decree No. 352, 16 women workers . 4.6 review and revision 4.6.1production technology secti on Office organized relevantdepartme nts units once a year to reviematerial changes on or after an accident, and biotech branch and that the workshopshoul d be timely to various reg ulations and safety rules be revised to ensure suitability and effectiveness. 4.6.3 revision of the file change approval form should be filled in, i ndi cating the causes andcha nges, a ppr oved by the Deputy incharge of security, General Manager of revision. 4.6.4 anew revised safety r