1. If vectors $\boldsymbol{a}, \boldsymbol{b}, \boldsymbol{c}$ satisfy $\boldsymbol{a}+2 \boldsymbol{b}+3 \boldsymbol{c}=\mathbf{0}$, and $|\boldsymbol{a}|=6,|\boldsymbol{b}|=5,|\boldsymbol{c}|=2$, then $2 \boldsymbol{a} \cdot \boldsymbol{b}+6 \boldsymbol{b} \cdot \boldsymbol{c}+$ $3 \boldsymbol{c} \cdot \boldsymbol{a}=$ $\qquad$ .
1. -86 .

From $\boldsymbol{a}+2 \boldsymbol{b}+3 c=\mathbf{0}$, we get
$$
\begin{array}{l}
0=(\boldsymbol{a}+2 \boldsymbol{b}+3 \boldsymbol{c})^{2}=\boldsymbol{a}^{2}+4 \boldsymbol{b}^{2}+9 \boldsymbol{c}^{2}+2(2 \boldsymbol{a} \cdot \boldsymbol{b}+6 \boldsymbol{b} \cdot \boldsymbol{c}+3 \boldsymbol{c} \cdot \boldsymbol{a}) \\
\Rightarrow 2 \boldsymbol{a} \cdot \boldsymbol{b}+6 \boldsymbol{b} \cdot \boldsymbol{c}+3 \boldsymbol{c} \cdot \boldsymbol{a}=-86
\end{array}
$$