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nhungtd0601
2 năm trước
Cho hình bình hành ABCD có góc A = 60o. Lấy E thuộc AD, F thuộc CD, sao cho DE = CF. Gọi K là điểm đối xứng của F qua BC. S là giao điểm của hai đường thẳng AK và AD. Chứng minh: a) Tam giác CKF cân và tính góc KCF (I là giao điểm của BC và KF) b) SC = SD c) Tam giác SEK đều d) AB // KE vẽ hình giúp mình luôn ạ
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