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khoin3214
2 năm trước
Bài 3: Cho tam giác ABC vuông tại A (AB < AC) có đường cao AD (D thuộc BC). a) Chứng minh: DAB và ACB đồng dạng. b) Đường phân giác của góc ABC cắt AC tại E. Từ C vẽ đường thẳng vuông góc với đường thẳng BE tại F. Chứng minh: AE. AB = EC. BD. c) Kẻ FH vuông góc với AC tại H. Chứng minh: 𝐵𝐶𝐹 ̂ = 𝐻𝐹𝐶 ̂. d) Gọi I là trung điểm của BC. Chứng minh ba điểm I, H, F thẳng hàng. Giúp mik vs ạ
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