Vector Algebra

If $\mathbf{r}_1=2 \hat{\mathbf{x}}, \mathbf{r}_2=2 \hat{\mathbf{y}}$, where $\hat{\mathbf{x}}$ and $\hat{\mathbf{y}}$ are unit vectors along the $X$-axis and $Y$-axis respectively, then the magnitude of $\mathbf{r}_1+\mathbf{r}_2$ is