Các câu hỏi tương tự
cho tam giac ABC can tai A co goc B=2A. phan giac B cat AC tai D
a, tinh so do cac goc cua tam giac ABC
b, CM: DA=DB
c, CM: DH=BC
Cho tam giac ABC co goc A = 60 do . Cac duong phan giac BD va CE cat nhau tai I . Tren canh BC lay M sao cho BM = BE . a) Chung minh tam giac MID can
b) ve duong thang vuong goc voi BI tai B va vuong goc voi CI tai C , chung cat nhau o K . CMR : 3 diem A,I,K thang hang
cho tam giac abc can tai a co goc bac =50do tren tia doi cua tia bc lay diem d tren tia doi cua tia cb lay diem e sao cho bd =ba ce=ca tinh goc dae
cho tam giac abc deu ve ben ngoai tam giac cac tam giac abd vuong can tai b tam giac ace vuong can tai c tinh so goc nhon cua ade
cho tam giac ABC co goc A = 64 do hai tia phan giac cua goc B va goc C cat nhau tai I
a+ tinh goc BIC
b) ke duong phan giac qua I song song voi BC cat AB tai M va AC tai N chung minh rang tam giac BMI va tam giac CNI can
c) chung minh MN=BN+CN
cho tam giac abc co cac tia phan giac goc abc cat ac tai d, tia phan giac goc acb cat ab tai e. tinh goc a biet be +cd=bc
cho tam giac abc vuong tai a co goc b bang 60 do tren canh bc lay diem h sao cho hb=ab duong vuong goc voi bc tai h cat ac tai d
a/ cm bd la tia phan giac cua goc adc
b/ chung to tam giac bdc can
cho tam giac ABC vuong tai A. Tia phan giac cua goc B cat AC tai D. Ke DE vuong goc BC tai E.
a) chung minh tam giac BAD = tam giac BED
b) goi H la giao diem cua BD va AE. Chung minh tam giac ABH = tam giac EBH. Tinh so do goc H
cho tam giac ABC co B=110 do C =50 do phan giac goc ngoai tai dinh A cat tia doi cua tia BC tai D tinh cac goc cua tam giac ABD
cho tam giac ABC vuong tai A co AB = 8cm, BC = 10cm a) Tinh AC, b) tren tia AC lay diem D sao cho AD = AC. Ve AE vuong goc BD tai E, ve AF vuong goc BC tai F. Chung minh tam giac ABE = tam giac ABF, c) Ve duong thang vuong goc BD tai D duong thang vuong goc BC tai C. Hai duong thang nay cat nhau ta M. Chung minh: tam giac MDC can, D) Chung minh: B,A, M thang hang