Question
If $\vec{a}$, $\vec{b}$, and $\vec{c}$ are unit vectors, such that $\vec{a} + \vec{b} + \vec{c} = \vec{0}$, then $3\vec{a} \cdot \vec{b} + 2\vec{b} \cdot \vec{c} + \vec{c} \cdot \vec{a} = \ldots$
If $\vec{a}$, $\vec{b}$, and $\vec{c}$ are unit vectors, such that $\vec{a} + \vec{b} + \vec{c} = \vec{0}$, then $3\vec{a} \cdot \vec{b} + 2\vec{b} \cdot \vec{c} + \vec{c} \cdot \vec{a} = \ldots$