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uzumakinaruto9669
2 năm trước
Cho tam giác abc nhọn(ab<ac) có 2 đường cao bd và ce cắt nhau tại h. a)chứng minh tam giác abd đồng dạng vs tam giác ace b)chứng minh hd.hb=he.hc c)ah cắt bc tại f.Kẻ fi vuông góc ac tại i.chứng minh IF/IC=FA/FC d)trên tia đối tia af lấy điểm n sao cho an=af.m là trung điểm cạnh ic.Chứng minh ni vuông góc fm Giúp mik với.Tks các bạn
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