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nhin85546
2 năm trước
Cho tam giác ABC vuông tại A (AB>AC) M là trung điểm BC.Trên tia đối của tia MA lấy D cho MD=MA. a) chứng minh AB=DC và AB//DC b) chứng minh tam giác ABC=tam giác CDA từ đó suy ra AM=BC/2 c) trên tia đối của tia AC lấy E sao cho AE=AC. Chứng minh BE//AM d) tìm điều kiện của tam giác ABC để AC=BC/2 e) gọi o là trung điểm của AB.chứng minh ba điểm E, O, D thẳng hàng. Giúp mình nha!!!
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