Bài tập 9 trang 28 SGK Hình học 12

A. 10                       

B. 6

 C. 8                        

D. 4

\(\begin{array}{l}A.\,\dfrac{{{a^3}\sqrt 2 }}{3}\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,B.\,\dfrac{{{a^3}\sqrt 2 }}{6}\\C.\,\dfrac{{{a^3}\sqrt 3 }}{4}\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,D.\,\dfrac{{{a^3}\sqrt 3 }}{8}\end{array}\)

A.  8                         

B. 7

C. 9                           

D. 6

A. 12                      

B. 10

C. 13                       

D. 11

\(A.\,\,\dfrac{{3a\sqrt {13} }}{{13}}\)        

\(B.\,\,\,\dfrac{{4a\sqrt {13} }}{{13}}\)  

\(C.\,\,\,\dfrac{{a\sqrt {13} }}{{13}}\)           

\(D.\,\,\dfrac{{2a\sqrt {13} }}{{13}}\)   

\(A.\,\,V = \dfrac{{{a^3}}}{6}\)     

\(B.\,\,\,V = \dfrac{{{a^3}}}{3}\)  

\(C.\,\,V = {a^3}\)      

\(D.\,\,V = \dfrac{{{a^3}}}{9}\)  

A. 20.          

B. 3.

C. 12.           

D. 5.

\(A.\,\,\,V = \dfrac{1}{2}Bh.\)           

\(B.\,\,\,V = Bh.\)  

\(C.\,\,\,V = \dfrac{1}{3}Bh.\)         

\(D.\,\,V = \dfrac{{\sqrt 3 }}{2}Bh.\)  

A. {5;3}.        

B. {3;4}.

C. {4;3}.        

D. {3;5}.

 \(A.\,\,\dfrac{V}{3}\)              

\(B.\,\,\dfrac{V}{4}\)  

\(C.\,\,\dfrac{V}{6}\)            

\(D.\,\,\dfrac{V}{2}\)