Two vectors $\overrightarrow{\mathbf{A}}$ and $\overrightarrow{\mathbf{B}}$ have precisely equal magnitudes. For the magnitude of $\overrightarrow{\mathbf{A}}+\overrightarrow{\mathbf{B}}$ to be 100 times larger than the magnitude of $\overrightarrow{\mathbf{A}}-\overrightarrow{\mathbf{B}},$ what must be the angle between them?