‘O’ is the origin in the cartesian plane. From the origin ‘O’ take point A in the North East direction such that $\left|\overline{\mathrm{OA}}\right| = 5.$ B is a point in the NorthWest direction such that $\left|\overline{\mathrm{OB}}\right| = 5.$Then $\left|\overline{\mathrm{OA}} \overline{\mathrm{OB}}\right|=$