Cho tam giac ABC co goc A = 90 do. Ve Tia phan giac Bd cua goc B ( D thuoc AC ). Tren canh BC lay E cho BE = BA
a) so sanh do dai doan AD va DE, so sanh goc EDC va ABC
b) cm AE vuong goc voi BD
cho tam giac ABC co goc A= 85 do, goc B=40 do
a, so sanh cac canh cua tam giac ABC
b, tren tia doi cua tia AB lay diem D sao cho AD=AC.Tren tia doi cua tia BA lay diem E sao cho BE=BC. So sanh do dai cac doan CD;CB;CE
Chao cac gia su va cac ban.Minh co 1bai toan chua lam duoc.Nhu lan truoc,minh da dat cau hoi ve hinh hoc.Lan nay minh xin dat mot cau nua,mong moi nguoi giup minh bai toan nay :
Cho tam giac ABC vuong tai A,co goc B =60 do.
a, Tinh so do goc C va so sanh do dai 3canh cua tam giac ABC
b,Ve BD la tia phan giac cua goc ABC(D thuoc AC).Qua D ve DK vuong goc voi BC(K thuoc BC) .Chung minh:tam giac BAD=tam giac BKD
c,C/minh :tam giac BDC can va K la trung diem BC
d,Tia KD cat BA tai I.Tinh do dai canh ID biet AB=3cm(lam tron ket qua den chu so thap phan thu nhat).
Neu ai, gia su co the tra loi duoc cau hoi nay thi xin nhan tin lai cho minh a.Minh xin cam on nhieuuuuuuuu(ve hinh nua nhe! )
Cho tam giac ABC co goc A =90 do . Tren cach BC lay diem E sao cho BE=BA.tia phan giac cua goc B cat canh AC tai D
a,So sanh do dai cac doan thang DA,DE
.b, Tinh so do goc BED
c, Chung minh BD vuong goc voi AE
D, So sanh so do cac goc ABC va goc CAE
Cho tam giac ABC can tai A co AD la duong trung tuyen
a)Chung minh tam giac ABD= tam gaic ACD va AD vuong goc voi BC
b)Cho AB=10cm,BC=16cm. Tinh do dai AD va so sanh cac goc cua tam giac ABC.
c) Ve duong trung tuyen CF cua tam giac ABC cat AD tai M. Tinh do dai AM.
d) Ve DH vuong goc AC tai H, tren canh AC va canh DC lan luot lay hai diem E,K sao cho AE=AD va DK=DH. Chung minh: EK vuong goc voi BC
|x-1,25|=2,75
Cho tam giac ABC co B=45°,C=75°. Phan giac BAC cat canh BC tai M. Qua M ke dg thang song song voi dg thang AB cat canh AC tai N.
1, tinh so do cac goc BAC va goc AMB
2,tinh so do cac goc cua tam giac AMN
cho tam giac abc, goc A tu, tren canh BC lay diem M, N sao cho BN=BA, CM=CA
a, so sanh goc AMC va ANB
b, so sanh canh AM va AN
c, biet goc ABC =40 do, goc ACB =30 do , tinh so do 3 goc cua tam giac AMN
Xin chao tat ca moi nguoi,giup mimh bai toan nay voi nak.(Toan lop 7-hinh hoc nha)
Cho tam giac ABC vuong tai A,AB=6cm,AC=8cm.
a)Tinh BC
b)So sanh goc ABC va goc ACB.
c)Tren canh BC dat diem H sao cho BH=BA.Ve duong thang di qua H vuong goc voi BC cat AC tai D.Chung minh:tam giac ABD=tam giac HBD,tu do suy ra BD la tia phan giac cua goc ABC.
c)Hai duong thang BA va HD keo dai cat nhau tai E.Chung minh tam giac CDE can.
Ai co cau tra loi dung,chinh xac nhat gui cho
minh nha. Minh cam on ban nhieu,nho la ve hinh nua nha ban!!!
cho tam giac abc vuong oa co canh BC=2AB. tinh so do cac goc cua tam giac
