Mathematics - Vector Question with Solution | TestHub

If $\bar{a},\bar{b},\bar{c}$ are unit vectors such that $\bar{a}$ is perpendicular to plane of $\bar{b}$ and $\bar{c}$ and the angle between $\bar{b}\&\bar{c}$ is $\frac{\pi }{3}$ the $|\bar{a}+\bar{b}+\bar{c}|$ is