Câu 1: Cho hình chóp S.ABCD có đáy là hình vuông cạnh a √2. ΔSAB vuông cân tại S và nằm trong mặt phẳng vuông góc với đáy. Gọi H là trung điểm của AB; K là trung điểm của CD. a) CMR: (SCD) ⊥ (SHK) b) Tính góc giữa các mặt phẳng: (SBC) và (ABCD); (SBC) và (SAB); (SCD) và (ABCD) c) Tính góc giữa: SC và (ABCD); SA và (ABCD). Câu 2: Cho lăng trụ đứng ABC.A'B'C' có đáy là tam giác vuông tại A; AB=a, BC=2a; AA'=a √3/2. Tính góc : a) (A'B, (ABC)); b) (A'C, (ABC)); (A'C, (ABB'A')) c) ((A'BC), (ABC))

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