Các câu hỏi tương tự
BAI1Cho 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.CMRa,BFMD,CDME,AEMF LA CAC HINH THANG CANb,goc DMEgoc EMFgoc DMFc,Trong ba doan thang MA,MB,MC doan lon nhat nho hon tong hai doan kiaBAI2Hinh thang can ABCD (AB//CD)co hai duong cheo cat nhau tai P,hai canh ben keo dai cat nhau tai Q .CMRPQ la duong trung truc cua hai day
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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 hinh chu nhat ABCD hai duong cheo AC va BD cat nhau tai O .Lay E la doem bat ky thuoc doan thang OA .Duong thang BE cat AD tai M . Qua D ve duong thang song song voiBM duong thang nay cat BC tai F va cat AC tai N. Chung minh tu giac BMDF la hinh binh hanh
1Cho tu giac loi abcd co ad=bc. Duong thang qua trung diem cua hai canh ab va cd cat ad va bc lan luot tai e va f. cmr <aem = <mfb
2Cho tu giac loi abcd co ab va cd ko song song voi nhau goi m, n lan luot la trung diem cua cac canh bc va ad. cmr mn< ab+cd/2
Cho tam giac ABC co duong trung tuyen AM Qua diem D Thuoc BC va duong thang song song voi AM cat AB va AC theo thu tu tai E va Fa, khi D di chuyen tren BC thi tong DE_DF ko doi b, Qua diem A ke duong thag song song BC cat EF tai K CMR K la trung diem cua EF
cho hinh thang ABCD ( AB// CD,AB<CD) qua A ke duong thang song song voi BC cat BD o E va cat CD o K . qua B ke duong thang song song voi AD cat AC o F va cat CD o I. cmr
a, DK=CI
b, EF//CD
c,AB^2=CD.EF
(((mình đang cần gấp ai giúp mình với)
cho hinh thang ABCD (AB song song CD , AB<AC ) . goi K , M lan luot la trung diem cua BD , AC . duong thang di qua K vuong goc voi AD cat duong thang qua M vuong goc BC tai Q . chung minh rang : a) KM song song AB .b) QD = QC
Cho hinh thang ABCḌ̣̣̣̣̣̣̣̣̣̣̣̣̣̣̣̣̣̣̣̣̣̣̣̣̣̣̣̣̣̣̣̣̣̣̣̣̣(AB//CD),O la giao diem cua hai duong cheo AC va BD. Qua O ke duong thang song song voi AB cat AD va BC lan luot o M va N. CHung minh OM = ON
Cho tam giac ABC va 1 diem D tren canh AB.Duong thang di qua D va //voi BC cat AC tai E va cat duong thang qua C //voi AB tai G . Noi BG cat AC tai H . Qua H ke duong thang //voi AB cat BC tại I(i)
CMR DA×EG=DB×DE
Cac ban giup minh voi minh voi lam
cho hinh thang ABCD(AB song song CD).duong thang song song voi day nho AB cat cac canh AD,BD,AC,,BC theo thu tu tai cac diem M,N,P,Q, chung minh MN₫PQ