cho 2 vecto \(\overrightarrow{a},\overrightarrow{b}\) thoa man \(\left|\overrightarrow{a}\right|=4,\left|\overrightarrow{b}\right|=3\) và \(\left|\overrightarrow{a}+2\overrightarrow{b}\right|=2\sqrt{7}\). Tính \(\left(\overrightarrow{a},\overrightarrow{b}\right)=????\)