Cho hình chóp đều . Gọi  là trọng tâm tam giác . Quay các cạnh của hình chóp đã cho quanh trục . Hỏi có tất cả bao nhiêu hình nón tạo thành.  

Chia sẻ

Một số câu hỏi khác có thể bạn quan tâm.

• Choose a word that has different stress pattern:

  loyalty             uncertain             sympathy             influence

• Choose a word that has different stress pattern:

  gossip            interest            between             friendship

• Choose the best answer for the following sentence:

  I do not want to listen to you. I am tired ___________ your criticisms.
   

• Choose the best answer for the following sentence:

  True friendship will _____________ as long as our lives.
   

• Choose the best answer for the following sentence:

  He advised me ____________ the facts before I made a decision ____________ the job.
   

• Choose the best answer for the following sentence:

  They have _______________ they cannot find time _________________.
  
  

• Choose the best answer for the following sentence:

  There ___________ mutual understanding between friends.
  
  
  

• Choose the word that has the underlined part pronounced differently from the rest:

  machinery                 march                    cheerfully                  merchant

• Choose the best answer for the following sentence:

  The water was so polluted that the explorers could not drink it.

• Choose the best answer for the following sentence:

  His doctor advised him ____________, but he found it impossible ______________ his habit.