Khối lăng trụ ABC.A’B’C’ có đáy là tam giác đều, a là độ dài cạnh đáy. Góc giữa cạnh bên và đáy là . Hình chiếu vuông góc cảu A’ trên (ABC) trùng với trung điểm BC. Tính thể tích khối lăng trụ đã cho là:            

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Một số câu hỏi khác có thể bạn quan tâm.

• Mark the letter A, B, C or D to indicate the correct answer to each of the following questions:

  There has been an announcement from the Principal that the students will not hear the bell ________ this week as it has broken.         

• Mark the letter A, B, C or D to indicate the correct answer to each of the following questions:   

  The young students always wish they ________ able to bring cellphone to schools.         

• Mark the letter A, B, C or D to indicate the correct answer to each of the following questions:

  Although thunder and lightning are produced at the same time, light waves travel faster ________, so we see the lightening before we hear the thunder.         

• Mark the letter A, B, C or D to indicate the correct answer to each of the following questions:   

  Have I told you about ________ the government is dealing?         

• Mark the letter A, B, C or D to indicate the correct answer to each of the following questions:

  Jane only makes cakes with the ________ butter.         

• Mark the letter A, B, C or D to indicate the correct answer to each of the following questions:

  The more effect you put in this project, ________.         

• Mark the letter A, B, C or D to indicate the correct answer to each of the following questions:

  You have to take the full course of your antibiotics even if you feel better, ________ your illness will simply return.         

• Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the following questions:

  Since the flood the number of homeless people ……………… dramatically.         

• Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the following questions:   

  Could you please tell me…………………………?         

• Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the following questions:   

  ___________, the young mother appeared visibly very happy after the birth of her child.