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sonanh1310
2 năm trước
Cho tam giác ABC vuông tại A ,kẻ đường cao AH .Từ H kẻ HD vuông góc với AB, HE vuông góc với AC .Chứng minh: a) tam giác ABC đồng dạng với tam giác HBA. b) chứng minh AF .AB = AE . AC
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