question_answer

Find the value of \[{{\sin }^{2}}(120{}^\circ -A)+{{\sin }^{2}}A+{{\sin }^{2}}(120{}^\circ +A).\]

A)  \[\frac{2}{3}\]                                     

B)  \[\frac{3}{2}\]

C)  \[\frac{5}{2}\]                         

D)  \[\frac{\sqrt{3}}{2}\]

E)  None of these