Chương II : Tam giác
Các câu hỏi tương tự
cho tam giac ABC vuong tai A ,co AC=2AB.lay D la trung diem cua AC .dung AH,CK vuong goc voii BC.
a) cm; goc ABC = goc CDK va tam giac AHB = tam giac CKD
b) cm : DA= DC =DH va KH = KC
c) goi I la trung diem cua BD . Cm: tam giac AHI = tam giac KHI tu do tinh soo do goc IHK
d ) duong thang di qua A song song voi BC cat DK tai M. cm : H , I , M thang hang
e) duong thang AI cat BC tai N . cm : NK =
Cho tam giac ABC vuong tai A co tia phan giac BD(\(D\in AC\)).Tren canh BC lay diem E sao cho AB=BE.Tren tia doi cua tia AB lay diem F sao cho AF=EC.Goi I la giao diem cua BD va FD.Chung minh rang
a)CM ΔABD=EBD, \(DE\perp BC\)
b)BD la duong trung truc cua doan AE
3)3 diem F,D,E thang hang
4)Tinh do dai doan FC khi AC = 5cm ,ACB = 30 do
cho tam giac ABC can tai A goi E la trung diem cua AB goi F la trung diem cua AC CMR tam giac ABF bang tam giac ACE
CMR EF song song BC
cho tam giac ABC , ve diem M laqtrung diemcua BC. Trentia doi cua tia Ma lay diem D sao cho MAMD.
a) Chung minh:tam giac ABMtam giac DCM b) Chung minh:AB// DC C) Ke BE vuong goc AM (E thuoc AM), CFvuong goc DM (F thuoc DM). Chung min...
Đọc tiếp
cho tam giac ABC , ve diem M laqtrung diemcua BC. Trentia doi cua tia Ma lay diem D sao cho MA=MD.
a) Chung minh:tam giac ABM=tam giac DCM b) Chung minh:AB// DC C) Ke BE vuong goc AM (E thuoc AM), CFvuong goc DM (F thuoc DM). Chung minh: Mla trung diem cua EF [ve hinh va giai bai tap ho to nhe]
cho tam giac ABC vng o A phan giac BD. DE vuong goc vs BC F la giao diemcua BA va ED a, BD la trung truc cua AE b, DFDC...
Đọc tiếp
cho tam giac ABC vng o A phan giac BD. DE vuong goc vs BC F la giao diemcua BA va ED a, BD la trung truc cua AE b, DF=DC c, AD<DC
Cho tam giác ABCco A=6cm,BC=8cm ,CÁ=10cm
a, Dinh dang tam giac ABC
b, Tren tia doi cua tia BC lay diem D sao cho BD=BC .Chung minh tam giac ACD can
c,Tren AB lay diem M .Chung minh rang MC=MD va MB la tia phan giac cua goc CMD
Cho tam giac ABC co AB=AC tia phan giac cua goc A cat BC tai M .Chung minh
tam giac ABC=TAM GIAC ACM
M la trung diem cua BC
AM vuong goc voi BC
Cho ΔABC co ∠A >90 d. Ke AD⊥AB va AD=AB (Tia phan giac AD nam giua AB va AC). M la trung diem BC. C/m: AM⊥DE
Cho tam giac ABC vuong tai A va M la trung diem AB ke MN vuong goc BC tai N Tren tia doi tia AB lay D sao cho AD=BN Ke ME vuong goc CD tai E Cac doan thang DN va ME cat nhau tai K Goi I la trung diem cua doan thang DK Tinh so do goc CIM