bai 3 ; cho tam giac abc . tren canh ab lay diem m , tren canh ac lay diem n sao cho bm = cn . goi i la trung giem doan bn , goi k la trung diem doan cm , duong thang ik cat ab tai p , cat ac tai q . chung minh rang tam giac apq la tam giac can .

cho tam giac ABC co AB=AC,lay diem M tren canh AB,diem N tren canh AC sao cho AM=AN(M khac A,B va N khac A,C).Goi O la giao diem cua BN va CM.Chung minh rang : a) BN=CM, b) tam giac BOM=tam giac CON, c) OA vuong goc voi BC

Cho tam giac ABC co dien tich la : 360 cm² . Tren canh AB lay diem M sao cho AM = 1/3 AB . Tren canh AC lay diem N sao cho AN = 3 x AC . Tinh dien tich tam giac AMN va CMN .

cho tam giac ABC tren canh AB  lay diem M tren canh AC lay diem N sao cho AM=1/3AB NC=2/3AC dien tich tam giac ABC gap dien tich AMN so kan la

cho tam giac ABC co dien tich bang 36cm2. tren canh AB lay diem M, tren canh AC lay diem Q va tren canh BC lau diem N sao cho AM=2 BM; BN= 2 CN; CQ = 2 AQ

a) tinh dien tich tam giac ABN

b) tinh dien tich tam giac MNQ

cho tam giac ABC can tai A. Tren canh AB,AC lan luot lay 2 diem M,N sao cho AM=AN. Goi giao diem cua BN va CM la I . Chung minh tam giac BIC can

cho tam giac ABC lay diem M tren canh AB sao cho AM=1/3 AB lay diem N tren canh AC sao cho AN = 2/3 AC tren canh BC lay diem P sao cho CP=1/3 BC tinh dien tich tu giac BMNP biet dien tich tam giac ABC la 108 cm2

cho tam giac ABC vong goc tai A co AB=6 cm,AC=8cm,BC=10 cm.Tren canh AB lay diem M sao cho AM= 4cm,tren canh BC lay diem N sao cho AN=2 cm,tren canh BC lay diem E sao cho BE=5 cm.Tinh:
a)chu ci va dien tich tam giac ABC.
b)diện tích tam giác MNE.

cho tam giac abcd tren canh ab lay diem m tren canh ac lay diem n sao cho an=1/3ac nc2/3ac dien tich abc gap dien  tam giac anm so lan la