SABC = 60 x 30 : 2 = 900 (m2)
SDCB = 1/3SABC = 900:3 = 300 (m2)
(DB=1/3AB; 2 tam giác có chung đường cao kẻ từ C)
SADC = 900-300 = 600 (m2)
Tương tự: SDCK = 1/3SADC = 600 : 6 = 200 (m2)
SADK= 600 – 200 = 400 (m2)
SDKG = SDGA = SADK : 2 = 400 : 2 = 200 (m2)
SGED = SGDA : 2 = 200 : 2 = 100 (m2)
SGEDK = SGED + SGDK = 100 + 200 = 300 (m2)
bai 4 :cho tam giac abc.bc =60 cm duong cao ah =30 cm lay d,e tren ab .ae =ed=db lay g,k tren ac :ag =gk=kc tinh dien tich tam giac aeg
cho tam giac ABC,duong cao AH.Tren AH lay diem D sao cho AD gap doi DH.Biet BH=4cm,BC=12 cm.Hay so sanh dien tich tam giac BCD voi dien tich tam giac ABH.
1.Cho tam giac ABC co canh day BC la 35cm , chieu cao AH la 24cm . Tren AH lay diem M sao cho MH = 1/3 AH . Tinh dien tich tam giac ABC va dien tich tam giac MBC
2.Cho tam giac ABC co dien tich la 28,8cm2 . Tren AB lay diem N sao cho AN = 1/3 NC . Noi M voi N . Tinh dien tich Tam giac AMN
cho dien tich ABC=20.25dm2 canh BC=50cm tren canh AC lay D sao cho AD=1/3 AC ke duong cao AH va DK cua tam giac ABC va tam giac DBC tinh do dai AH va DK
Cho hinh tam giac ABC co chieu cao AH, tren AH lay M sao cho MH= 1/3 AH. Noi M voi B. BH=6,4cm, HC= 7,2cm biet dien tich tam giac BMH la 11,2 cm2. Tinh dien tich tam giac ABC.
Cho tam giac ABC .Tren canh AB lay diem D sao cho AD gap doi BD .Tren canh AD lay lay diem E sao choAE gap doi EC .Noi B voi E , C voi D ,doan BE cat CD o G . So Sanh dien tich tam giac GDB voi diwn tich tam giac
cho hinh tam giac ABC co gocA la goc vuong va canh AB=6 cm,canh AC = 9 cm tren canh AB lay diem M va N sao cho AM=MN=NB,tren canhAC lay diem K va H sao cho AK=KH=KC.tinh dien tich hinh tu giac MNHK
cho hinh tam giac ABC deu co canh dai 6cm ,tren canh BC lay E sao cho BE=EC. BH la duong cao ha tu dinh B cua tam giac ABC va BH=3 cm .EH chia tam giac thanh 2 phan dien tich tu giac ABEH gap doi dien tich CEH
a,tinh do dai doan thang AH
b, tinh dien tich hinh tam giac AHE
Cho tam giac ABC co day BC=36cm va gap ruoi chieu cao ha tu A
a) tinh dien tich tam giac ABC
b)Tren AB lay diem M sao cho BM=1/3AB . Tu M ke duong song song voi BC cat AC tai N . Noi M voi N . Tinh dien tich tu giac MNCB?
