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gianglth78
2 năm trước
Bài 5: Cho tam giác ABC vuông tại A có AB = 6cm, BC = 10cm, đường cao AH . a) Chứng minh ABCđồng dạng HAC. b) Tia phân giác của góc ABC cắt cạnh AC tại I. Tính IC. c) Qua C kẻ đường thẳng vuông góc với BI tại K. Gọi E là giao điểm của BA và CK. Chứng minh rằng EA.EB = EC.EK từ đó suy ra tam giác EAK đồng dạng tam giác ECB d) Gọi D là hình chiếu của K trên BE. Chứng minh rằng: (BK/KE)^2=BD/DE
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