Ôn tập toán 7
Các câu hỏi tương tự
tam giac abc co hai duong trung tuyen bm va cn .tren tia doi cua tia mb lay diem d sao cho md =mb .tren tia doi cua tia cn lay diem e sao cho ne=nc.cminh d ,a ,e thang hang
cho tam giac ABC co AB<AC,M la trung diem cua BC.tren doan thang AM lay diem I bat ki(I \(\ne\)A;I\(\ne\)M)lay diem D tren tia doi cua MA sao cho MD=MI
a.chung minh tam giac MIB=MDC
b/Chung minh BI song song DC,BD song song IC
cho tam giac ABC voi do dai 3canh la AB = 3cm , Bc=5cm, Ac= 4cm.
a) tam giac do la tam giac gi? vi sao ?
b) tren canh Bc lay diem D sao cho BA =BD. tu D ve Dx vuong goc voi BC (Dx cat AC tai H).Chung minh BH la tia phan giac goc ABC
c) Ve trung tuyen AM. chung minh tam giac ABM can
Cho tam giac ABC can tai A, tren AB lay D, tren tia doi cua tia CA lay E sao cho BD=CE. Noi D vs E. Goi I la trung diem cua DE. CM: B,I,C thang hang
cho tam giac ABC can o A co goc A =40 do . duong trung trc AB cat BC o D
a, tam giac ABD la tam giac gi ? vi sao?
b, tinh goc BAD; goc CAD
c, tren tia doi cua tia AD lay diem M sao cho AM=CD CM: tam giac BMD la tam giac can
Tam giac ABC vuong tai A, phan giac BD. Qua D ke d.thang vuong goc voi BC tai E.
a) CM: tam giac BAD = tam giac BED
b) BD la trung truc cua AE
c) AD <DC
d) tren tia doi AB lay diem F sao cho AF =CE. CM: ba diem E, D, F thang hang
Cho tam giac ABC can tai A.Tren can AB lay diem D,tren can AC lay diem E sao cho AD=AE.Goi M la giao diem cua BD va CD. Chung minh:
a) cac hinh chieu cua BD va CE tren BC bang nhau
b) BE=CD
c) tam giac BMD =tam giac CME
d) AM la tia p/g cua goc BAC
e) BE nho hon BC+DE:2
giup mk nha m. n can gap tick Cho
cho tam giac ABC goi M la trung diem cua BC tren tia doi cua tia MA lay 1 diemK sao cho MA=MK. CMR:
a) tam giac AMB= tam giac KMC
b) AB//KC
Cho tam giac abc co
Ak vuong goc bc
Tren tia doi ka lay diem m sc ka=km
Cm: tg kab= tg kmb. Tinh goc mab
Tren tia kb lay diem d sc kd= kc. Tia md cat ab tai n. Cm: mn vuong goc ab.
S/s: md + db voi ab