Các câu hỏi tương tự
Cho goc xOy = 90 trong goc xOy ve tia OC,OD sao cho aOc=bOd=60 voi a thuoc ox va b thuoc oy
a)tinh so do cua goc aod,doc,cob
b)tren nua mat phang bo oa co chua tia ob ve tia oe sao cho ob la phan giac cua goc doe
chung to OE vuong goc OC
cho xOy la goc nhon biet Oz la tia phan giac cua xOy tren nua mat phang bo Ox ta lay A tren nua mat phang Oz lay I tren nua mat phang Oy ta lay B ao cho AB cat IO tai H va AH=HB
a)CM AIH=IBH
b)CM AOH=BOH
c)CM AIH và IBH vuong goc
cho goc nhon xoy. diem H nam tren tia phan giac cua goc xoy. tu H dung cac duong vuong goc xuong hai canh Ox va Oy (A thuoc Ox va B thuoc oy).
a.chung minh tam giac hab la tam giac can
b.Goi D la hinh chieu cua A tren tia Oy,C la giao diem cua AD vs OH. Chung minh BC vuong goc vs Ox
c.Khi goc xOy=60 do,chung minh OA=2OD
Cho tam giac ABC co goc A < 90o ; AB = AC; AM la tia phan giac cua goc A (M thuoc BC)
a. CM goc B bang goc C
b. Tren cung mot nua mat phang bo AB khong chua diem C ke tia Ax vuong goc voi AB, tren nua mat phang bo AC khong chua diem B ke tia Ay vuong goc voi AC. Tren tai Ax va Ay lan luot lay 2 diem N va P sao cho AN=AP. CM rang BP=CN
c.CM NP song song voi BC
cho goc xOy vuong tren Ox lay A tren Oy lay B sao cho OA=OB lay M la trung diem cua doan AB
a) OM la trung truc cua AB
b)Tu A ke duong thang vuong goc voiOx tu B ke duong thang vuong goc voi Oy chung cat nhau tai y.Cm oy la phan giac goc AOB
c)CM O,Y,M thang hang
cho tam giac ABC nhon tren nua mat phnag co chua A bo BC ve tia Bx vuong goc voi BC tren tia do lay D sao cho BD=BC tren nua mat phang co hcua diem C bo AB ve tia By vuong goc voi AB tren tia do lay diem E sao cho BE=BA goi giao diem cua DA voi BC va EC theo thu tu la H,K tinh goc BKA
cho tam giac ABC co goc a nhon M la trung diem cua BC tren tia doi cua tia MA lay diem D sao cho MA=MD chung minh BAM=CDM chung minh AC=AD tren nua mat phang Bo AB ko chua C ve tia Ax vuong goc AB tren nua mat phang bo AC ko chua B ve tia Ay vuong goc AC tren tia Ax lay Diem P sao cho AP=AB tren tia Ay lay diem Q sao cho AQ=AC chung minh tam giac ABQ= tam giac APC goi giao diem cua DA va PQ la K chung minh AK vuong goc PQ
cho goc xoy =50 do. lay diem A tren tia ox . tren cung 1 nua mat phang bo ox chua tia oy, ve tia ot sao cho oy cat nhau tai B va goc oAt =80 do. goi at' la tia phan giac cua goc xAt
a) chung minh At'song song voi Oy
b) tren nua mat phang ko chua diem A bo duong thang oy ve tia Bn song song Ox
Cho tam giac ABC .goc A {90* . tren nua mat phang bo AB ko chua diem C, ve Ax vuomg goc voi AB, tren do lay D sao choAD=AB .tren nua mat phang bo AC, ko chua diem B ,ve Ay tren do lay E sao cho AE=AC a cmr BE=CD b duong thang AC va ED co vuong goc voi nhau ko?