$${\vec a = \begin{pmatrix}a_1 \\ a_2 \\ a_3\end{pmatrix}, \vec b = \begin{pmatrix}b_1 \\ b_2 \\ b_3\end{pmatrix} \text{ ja } \; \vec c = \begin{pmatrix}c_1 \\ c_2 \\ c_3\end{pmatrix}}$$