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nguyenthomadmid
2 năm trước
Cho tam giác ABC vuông tại A ( AC > AB ) . Kẻ tia phân giác góc B cắt AC tại E. Từ C hạ đoạn thẳng CD vuông góc với tia phân giác BE ( D thuốc BE ) a, Chứng minh tam giác AEB đồng dạng tam giác DEC . AB.DE = DC.AE b, chứng minh góc ECD bằng góc EBC c, Cho AB = 3 cm , AC = 4 cm , tính AC , AE , DB giúp mình với
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