bai 1: Cho tam giac ABC co goc A =\(90^0\)duong phan giac BD. Ke DH vuong goc voi Bc (H thuoc Bc). Goi E la giao diem cua 2 duong thang AB va HD.
Chung minh rang
a, tam giac ABD= tam giac HBD b,goc AED= goc HCD c, AD nho hon DC d, BD vuong goc EC
bai4: Cho tam giac ABC vuong tai A, co AB =6cm , Bc =10cm
1, Tinh do dai doan thangCa
2, Tia phan giac cua goc B cat tai Ac tai E, ke EM vuong goc voi BC (M thuoc Bc)
a, chung minh tam giac BAE= tam giac BME
giup to voi moi nguoi
1) cho I thuoc AB. tren cung nua mat phang bo AB. ve cac tam giac AIC va BID can. goi M, N lan luot la trung diem AD va BC. CMR tam giac IMN deu.
2) cho tam giac ABC co AB=6cm, BC=10cm, AC=4,5cm. tinh chu vi tam giac BDC.
1) Cho tam giac ABC co AB=8cm, AC=6cm, BC=10cm.
a) Chung minh rang tam giac ABC vuong .
b)Tren tia doi cua tia AB lay diem D sao cho AD=1cm. Tinh do dai doan thang CD
cho tam giac ABC can tai A co canh day bang 14 cm, ke Ad la tia phan giac cua goc BAC( D thuoc BC). tinh do dai canh AB biet AD= 15cm
cho tam giac ABC can tai A co canh day bang 14 cm, ke Ad la tia phan giac cua goc BAC( D thuoc BC). tinh do dai canh AB biet AD= 15cm
cho tam giac abc vuong tai A co ab bang 6cm,ac bang 8cm,duong phan giac B I.ke h I vuong va goc voi bc[h thuoc bc].goi k la giao diem cua ab va IH.
cho tam giac ABC co ÂB=6cm;AC=8cm;BC=10cm.
a,CMR;tam giac ABC vuong tai A
b;ve tia phan giac BD cua goc ABC (d thuoc AC)
Tu D kẻ DE vuong goc BC (Ẻ thuoc BC)
CM;DA=DE
c,BD la trung truc cua EC
cho tam giac ABC co AB be hon AC, AD laf tia phan giac cua goc BAC(D thuoc BC). Tren canh AC lay diem E sao cho AE=AB.C/m rang tam giac ABD=tam giac AED, CD lon hon DB
cho tam giac ABC co A = 90 do AB=6cm Ac= 8cm
a tinh BC
b so sanh cac goc cua tam giac ABC
c lay M thuoc AB , N thuoc AC so sanh BC va MN