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! )
giup minh giai cau d bai nay voi toan lop 7 nhe:
Cho tam giac vuong o C,co goc A = 60 do
tia phan giac cua goc BAC cat BC o E
ke EK vuong goc vs AB(K thuoc AB)
a)C/m AC=AK va AE vuong goc vs CK
b)c/m KA=KB
c)c/m EB>AC
d) Ke BD vuong goc vs tia AE (D thuoc tia AE).
C/m 3 duong thang AC,BD,KE cung di qua mot diem
Cam on mn
Cho tam giac ABC co AB<AC,phan giac AM. Ten tia AC lay N sao cho AN=AB.Goi K la giao diem cua AB voi MN .CMR:
a)MB=MN
b)tam giac MBK=tam giac MNC
c)AM vuong goc voi KC va BN//KC
d)AC-AB>MC-MB
Lam on lam ho minh vi mai minh phai nop ,xin cam on
cho tam giac ABC ,O la diem nam trong tam giac
a)chung minh rang goc BOC=goc A+ goc ABO+ goc ACO
b) biet goc ABO+ goc ACO= 90 -A/2 va tia BO la tia phan giac cua goc B chung minh rang tia CO l tia phan giac cua goc C
ai giup minh vs bay ruoi minh on minh tick cho
Cho tam giac ABC can tai A. Phan giac AM \(\left(M\in BC\right)\), co AB = 5cm, BC = 6cm
a) Chung minh: tam giac AMB = tam giac AMC
b) Chung minh: Am vuong goc BC
c) Tinh AM
d) Qua B ve duong thang a vuong goc voi AC va cat AM tai H. Chung minh: CH vuong goc AB
MINH DANG CAN RAT RAT GAP NHO CAC BAN GIAI GIUM CHO MINH ( cac ban muon giai phan a, b, c ko thi tuy nhung nho cac ban giup minh phan d voi )
CAM ON CAC BAN NHIEU
cho tam giac ABC co 3 duong trung tuyen AI,BE,CF cat nhau tai G.Tren tia doi cua tia IA lay M sao cho IM=IG Tren tia doi cua tia EB lay N sao cho EN=EG.TRen tia doi cua tia FC lay P sao cho PF=FG
CMR:
a) tam giac MNP=tam giac ABC
b)G la trong tam cua tam giac MNP
cac ban giup minh nhe minh tick cho .Cam on
cho tam giac abc vuong c co goc a=60do ,tia phan giac goc a cat bc o e.ke ekvuong goc voi bc,bdvuonh goc voi ae.cm:
a)ak=kb
b)ad=bc
cho tam giac abc vuong c co goc a=60do ,tia phan giac goc a cat bc o e.ke ekvuong goc voi bc,bdvuonh goc voi ae.cm:
a)ak=kb
b)ad=bc
Cho tam giac ABC can tai B ke BH vuong goc AC ( H thuoc AC )
a) Chung minh: HA = HC
b) Ke HD vuong goc AB ( D thuoc AB ), HE vuong goc BC ( E thuoc BC ). Chung minh: HD = HE
c) Chung minh: tam giac BDE can
d) Chung minh: \(BE^2+DH^2=BC^2-HA^2\)
MINH DANG CAN GAP NHO CAC BAN GIUP CHO ( phan a, b, c cac ban co the lam hoac ko thi tuy nhung nho cac ban giup minh phan d )
CAM ON CAC BAN NHIEU