Cho tam giac ABC vuong tai A (AB<AC),duong cao AH.Goi O la trung diem cua BC,D la diem doi xung cu A qua O

a)Chung minh ABDC la hinh chu nhat

b)Tren tia doi cua tia HA lay diem E sao cho HE=HA.Chung minh tam giac AED vuong va BE vuong goc voi voi CE

c) Goi M,N lan luot la hinh chieu cua E len BD va CD,EM cD tai K.Chung minhDE=DK

d)CM :H,M,N thang hang

giup mik nha moi nguoi

cho tam giac ABC can tai A,trung tuyen AM.Goi D la diem doi xung cua A qua M.Goi k la trung diem cua MC,E la diem doi xung cua D qua K

a) Chung minh tu giac ABCD la hinh thoi

b)chung minh tu giac AMCE la hih chu nhat

c)AM va BE cat nhau tai I

CM:I la trung diem BE

d) CM AK,CI,EM dong quy

moi nguoi cuu minh voi

please

viet mot bai van tu su :em giup mot ba cu qua duong luc dong nguoi

Xin hay cuu minh nha moi nguoi

nge tin ban duoc ket qua cao trong hoc tap em hay viet thu chuc mung va hoi tham suc khoe cua ban

ai van hay chu tot giup minh di nao

ahg vuong vung minh thi

cho tam giac abc can tai a,trung tuyen AM.goi D la diem doi xung cua A qua M.Goi k la trung diem cua MC,Ela diem doi xung cua D qua K

a)Chung minh tu giac ABCD la hinh thoi

b)Chung minh tu giac AMCE la hinh chu nhat

c)AM va BE cat nhau tai I.Chung minh I la trung diem BE

d)CM AK ,CI ,EM dong quy

moi nguoi giup minh nha.

Thanks moi nguoi nhieu lam

phan tu X co phan tu khoi gap 2 lan phan tu khoi cua Oxi ,X tao nen tu 2nguyen to S va O.Xac dinh cong thuc hoa hoc cua X

Moi nguoi giup mik nha

Minh thanks moi nguoi nhieu