Answer:
A = [tex]\frac{5\pi }{6}[/tex]
Step-by-step explanation:
Given that Cos A = [tex]-\frac{\sqrt{3} }{2}[/tex]
cos A = [tex]cos (\pi -\frac{\pi }{6} )[/tex]
A = [tex]\pi - \frac{\pi }{6}[/tex]