\(\vec{a}\ (0;1),\mid \vec{b} \mid=2,\angle{(\vec{a},\vec{b})}=60^\circ.\) Найдите \(\mid{\vec{a}+2\vec{b}}\mid.\)
\(\sqrt{23}\)
\(\sqrt{11}\)
\(\sqrt{21}\)
\(\sqrt{17}\)
\(\sqrt{13}\)