cho hinh tam giac ABC co dien tich 516 m2. tren canh BC lay hai diem P,Q sao cho BP = PQ = QC . tu P ke duong thang song song voi AC , tu Q ke duong thangsong song voi AD , HAI DUONG THANG NAY CAT NHAU TAI DIEM M . tinh dien tich hinh tam giac bcm
cho tam giác abc = 612 cm2 tren canh bc lay diem p,q sao cho pb=pq=qc ke diemp duong thang song song voi ac tu diem q song song voi ab hai duong thang cat diem m tinh Sbms
cho hinh thang ABCD. tren AB lay 2 diem M va N ke hai duong sao cho doan AM=ND=AD/4. Tu M va N ke 2 duong song song voi AB va CD, chung cat canh BC tai P va Q. Noi NP,QN. hay chung to rang dien tch hinh thang MPQN=1/2 dien tich hinh thang ABCD
Cho tam giac ABC vuong tai A co chu vi bang 48 m biet canh goc vuong thu nhat bang 3/3 canh goc vuong thu 2,canh BC bang 20 cm.
a)Tinh dien tich tam giac ABC
b)Diem M la diem chinh giua canh AB.tu M ke duong thang song song AC diem N la diem chinh giua canh AC,tu N ke duong thang song song voi AB hai duong thang vua ke cat nhau tai I.Tinh dien tich tu giac MICA.
c)Tinhs dien tich tu giac MICA
giup mk nha mk dag can gap
a) s=(14+14)/2
S=14 m2
b) S(MICA)= 28m2
c) S(MICK)=73.5m2
cho tam giac ABC , diem D thuoc canh BC .Qua D ke duong thang song song voi AC , cat AB o I .Qua D ke duong thang song song voi AB , cat AC o K.a)Tu giac AIDK la hinh gi? b)Diem D o vi tri nao tren canh BC thi AIDK la hinh thoi?
a Xét tứ giác AIDK ta có DI song song với AC(gt)
DK song song AI(gt)
Vậy tứ giác AiDK là hình bình hành(dhnb)
b Để AIDK là hình thoi thì D là trung điểm
cho tam giac ABC vuong goc tai AB.ab=20cm, AC= 15cm. tren ab lay diem M sao cho M=4cm. tu M ke duong thang song song voi AC cat BC tai N. tinh dien tich MNCA.
BAI1
Cho tam giac deu ABC .Diem M nam trong tam giac do.Qua M ke duong thang song song voi AC va cat BC o D,ke duong thang song song voi AB va cat AC o D,ke duong thang song song voi BC va cat AB o F.CMR
a,BFMD,CDME,AEMF LA CAC HINH THANG CAN
b,goc DME=goc EMF=goc DMF
c,Trong ba doan thang MA,MB,MC doan lon nhat nho hon tong hai doan kia
BAI2
Hinh thang can ABCD (AB//CD)co hai duong cheo cat nhau tai P,hai canh ben keo dai cat nhau tai Q .CMR
PQ la duong trung truc cua hai day
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?
cho tam giac ABC co dien tich la 283,5 cm2 day BC dai 27 cm.diem M tren AC va cach C mot doan bang 1/3 AC,tu M ke duong song song voi day Bc cat AB tai diem N.tinh dien tich hinh thang MNBC
cho tam giac abc diem m thuoc bc .qua m ke duong thang song song voi ab cat ac tai d. qua m ke duong thang song song voi ac cat ab o e
a adme la hinh gi
b tim vi tri cua m tren bc de tu giac adme la hinh thoi
c,tim dieu kien cua tam giac abc de tu giac adme la hinh chu nhat