cho 4 diem ABCD thuoc duong tron o sao cho AB= CD
Chung minh tam giac Aob= tam giac COD ko can ve hinh co cách lam la duoc
Những câu hỏi liên quan
1. cho bon diem A,B,C,D thuoc duong tron (O) sao cho AB=CD.chung minh rang.
a,tam giac AB=tam giac COD
b,goc AOB=goc COD
Cho nua duong tron (o) duong kinh AB va C la diem chinhgiua cung AB. Lay M thuoc cung BC va N thuoc tia Am sao cho AN=Bm.Ke day CD//AM
A chung minh tam giac ACN=tam giac BCM b. Chung minh tam giac CNM la tam giac vuong can
c. tu giac ANCD la hinh gi?vi saop?
cho 4 diem A,B,C,D thuoc duong tron tam O sao cho AB=CD chung minh rang tam giac AOD = tam giac COD
Cho 4 diem thoc duong tron tam o biet ab= cd a)tam giac aob=tam giac cod
B)aob=cod
cho goc bet xoy ve tia oy sao cho xy = 5/4 yoz
a, tinh xoy va yoz
b ke tia ot sao cho toy = 80 do tia oy co la tia phan giac cua toz ko vi sao
c , qua o ke them 20 duong thang nua sao cho cac duong thang nay deu ko chua cac tia ox,oy,oz ve duong tron tam o ban kinh r goi a la tap hop cac giao diem cua duong tron noi tren voi cac goc co o trong hinh ve .tinh so tam giac ma cac dinh cua no deu thuoc tap hop a
cho goc bet xoy ve tia oy sao cho xoy = 5/4 yoz
a, tinh xoy va yoz
b, ke tia ot sao cho toy = 80 do tia oy co la tia phan giac cua toz ko? vi sao ?
c , qua o ke them 20 guong thang nua sao cho cac duong thang nay deu ko chua cac tia ox,oy,oz ve duong tron tam o ban kinh r goi a la tap hop cac giao diem cua duong tron noi tren voi cac goc o co trong hinh ve tinh so tam giac ma cac dinh cua no deu thuoc tap hop a
1/cho tam giac ABC can tai A ( goc A900) cac duong cao AD va BE cat nhau tai H ( D thuoc BC, E thuoc AC) a/CM tu giac DHEC noi tiep duong tron b/chung minh EDBD va goc HBDgoc HCDc/Goi O la tam cua duong tron ngoai tiep tam giac AHE.CM rang ED la tiep tuyen cua duong tron (O)2/cho ram giac ABC co ba goc nhon noi tiep duong tron (O).Hai duong cao AD va BJ cat nhau tai Ha/CM;tu giac CDHK noi tiep b/ve d.kinh AF .tia AD cat (O)tai E.CM BC//EFc/CMR; AD/HDBD.CDb/goi I la trung diem cua BC .CMR: H,I,F...
Đọc tiếp
1/cho tam giac ABC can tai A ( goc A<900) cac duong cao AD va BE cat nhau tai H ( D thuoc BC, E thuoc AC)
a/CM tu giac DHEC noi tiep duong tron
b/chung minh ED=BD va goc HBD=goc HCD
c/Goi O la tam cua duong tron ngoai tiep tam giac AHE.CM rang ED la tiep tuyen cua duong tron (O)
2/cho ram giac ABC co ba goc nhon noi tiep duong tron (O).Hai duong cao AD va BJ cat nhau tai H
a/CM;tu giac CDHK noi tiep
b/ve d.kinh AF .tia AD cat (O)tai E.CM BC//EF
c/CMR; AD/HD=BD.CD
b/goi I la trung diem cua BC .CMR: H,I,F thang hang
3/cho tam giac nhon ABC noi tiep duong tron tam O,duong cao BHva CK lan luot cat duong tron tai Eva F
a.CMR: tu giac BKHC noi tiep
b.CM: A la diem chinh giua cu cung EF
c.CM:OA//EF
d.CM:EF//HK
4/cho tam giac ABC vuong tai A co AB<AC.Ke duong cao AH.Tren HC lay diem D sao cho HD=Hb
a/CMR:tap giac ABD can
b/Tu C ke CF vuong goc voi AD keo dai tai E
Chung minh tu giac AHEC noi tiep duoc trong 1 duong tron .Xac dinh tam O cua duong tron nay
c/CM:AB.ED=HB.CD
cho duong tron tam (o,r) duong kinh bc;a la 1 diem nam tren duong tron(a khong trung voi b,c).duong phan giac trong ad(d thuoc bc)cua tam giac abc cat duong tron tam o) tai diem thu 2 là m,ve duong thang de vuong goc voi ab(e thuoc ab),df vuong goc voi ac(f thuoc ac).chung minh aedf noi tiep.2 chung minh ab.ac=am.ad
1/ cho tam giac ABCco 3 goc nhon noi tiep duong tron (O).Hai duong cao AD va BKcat nhau tai Ha/CM tu giac CDHK noi tiep duong tron b/Ve duong kinh AF tia AD cat (O)tai E.CM BC//EFc/CMR.AD.HDBD.CD2/ cho hinh binh hanh ABCD co dinh D thuoc duong tron duong kinh AB Tu B ha BN vuong goc voi AC ; tu D ha DM vuong goc voi AC.Chung minha/.tu giac CBMD noi tiep duong tronb/tan giac ACD dong dang tam giac BDNc/DB.DCDN.AC3/cho tam giac ABC can tai A (A900) cac duong cao AD va BE cat nhau tai H ( D thuoc...
Đọc tiếp
1/ cho tam giac ABCco 3 goc nhon noi tiep duong tron (O).Hai duong cao AD va BKcat nhau tai H
a/CM tu giac CDHK noi tiep duong tron
b/Ve duong kinh AF tia AD cat (O)tai E.CM BC//EF
c/CMR.AD.HD=BD.CD
2/ cho hinh binh hanh ABCD co dinh D thuoc duong tron duong kinh AB Tu B ha BN vuong goc voi AC ; tu D ha DM vuong goc voi AC.Chung minh
a/.tu giac CBMD noi tiep duong tron
b/tan giac ACD dong dang tam giac BDN
c/DB.DC=DN.AC
3/cho tam giac ABC can tai A (A<900) cac duong cao AD va BE cat nhau tai H ( D thuoc BC, E thuoc AC )Cm ;Tu giac DHEC noi tiep duong tron CM;ED=BDva goc HBD = goc HCDgoi O la tam cua duong tron ngoai tiep tam giac AHE.Chung minh rang ED la tiep tuyen cua duong tron (O)