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 can tai a . tren canh ab lay diem m tren tia ac lay diem n sao cho bm=cn ,duong thang bc cat mn tai i. chung minh i la trung diem cua mn

cho tam giac ABC tren tia doi cua tia AB lay diem D sao cho AC= AD. tren tia doi cua tia AC lay diem E sao cho AE=AB

a) chung minh tam giac ADE= tam giac ACB

b)goi M la trung diem cua BE chung minh tam giac ABM bang tam giac AEM

c) duong thang AM cat CD tai N. Chung minh AN vuong goc CD

Cho tam giac abc vuong tai a. Ke ah vuong goc voi bc tai h. Tren tia doi cua tia ha lay diem d sao cho ha=hd.

a) chung minh tam giac ahd=tam giac dhc

b)tren tia dc lay diem k sao cho c la trung diem cua dk. Chung minh ak||bc

c) tu c ke duong thang song song voi ab cat ak tai m. Doan thang bm cat ac tai q. Chung minh am+cm>2mq

tam giac abc co ab bang 12 cm ac bang 15 cm bc bang 16 cm tren ab lay m sao cho am bang 3cm tum ke duong thang song song bc cat ac tai n cat trung tuyen ai tai k a tinh mn b chung minh k la trung diem mn c tren tia mn lay p sao cho mp bang 8 cm noi pi cat ac tai q chung minh tam giac qic dong dang voi tam giac aiqn

cho tam giac abc tren ab lay diem m sao cho am =1/2 ab .tren ac lay diem n sao cho an = 1/2 nc.bn va cm cat nhau tai k. tinh sabc biet dien tich akc =42 dm

cho tam giac ABC tren AB lay diem M sao cho AM bang 1/3 AB tren AC lay diem N sao cho AN bang 2/3 AC  tren BC  lay diem E sao cho BE bang 1/3 BC biet dien tich tam giac MNE la 18 cm Tinh dien tich tam giac ABC

Cho tam giac ABC . Tren AB lay diem M sao cho AM = 2 MB , tren canh AC lay diem N sao cho AN = 1/2 NC . Ha AH,BE,CF vuong goc voi duong thang MN (H,E,F ) nam tren duong thang MN . Hãy chứng minh A

cho tam giac abc tren ab lay diem m sao cho am= 1/2 x mb tren ac lay diem n sao cho an = 1/3 x nc. bn cat cm tai o so sanh s obc voi s abc