Chóp S.ABC, \(SA\bot \left( ABC \right),\,\,SA=a,\,\,\Delta ABC\)đều, \(AB=a\). Tính \(\widehat{\left( SB;AC \right)}\) ?
A. \(\arccos \frac{1}{5}\)                                  
B. \(\arccos \frac{1}{4}\)                                  
C. \(\arccos \frac{1}{2\sqrt{2}}\)                     
D. \(\arccos \frac{1}{\sqrt{2}}\)

Các câu hỏi liên quan