2.
设\( \overrightarrow{a}\),\( \overrightarrow{b}\)是非零向量,且\( \overrightarrow{a}\),\( \overrightarrow{b}\)不共线\(.\)则“\(| \overrightarrow{a}|=| \overrightarrow{b}|\)”是“\(| \overrightarrow{a}+2 \overrightarrow{b}|=|2 \overrightarrow{a}+ \overrightarrow{b}|\)”的\((\) \()\)