The vector $\overrightarrow{a}+\overrightarrow{b}$ bisects the angle between the non-collinear vectors $\overrightarrow{a}$ and $\overrightarrow{b}$ if__________.

Question

$\begin{array}{1 1} |\overrightarrow a|=|\overrightarrow b| \\ |\overrightarrow a|=2|\overrightarrow b| \\ 2 |\overrightarrow a|=|\overrightarrow b| \\ If \;\overrightarrow a\; and \;\overrightarrow b\; are\; \perp\end{array}$