Cho tam giác ABC vuông tại A , đường cao AH, trung tuyến AM . Gọi D là trung điểm AB, lấy điểm E đối xứng với M qua D. a. Chứng minh : M và E đối xứng với nhau qua AB. b. Chứng minh : Tam giác MBE là hình thoi. c. Chứng minh AB.AC = BC.AH d. Kẻ HK vuông góc với AB tại K, HI vuông góc với AC tại I. Chứng minh IK vuông góc với AM C,ab.ac=bc.ah.giúp mk ý này với

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