Lines that are found on the same plane are called coplanar lines.
Lines \(k\) and \(r\) lie on the same horizontal plane. Therefore, they are coplanar.
Similarly, lines \(m\) and \(n\) are coplanar because they lie on the same vertical plane.
However, lines \(m\) and \(r\) are not coplanar because they are found on different planes.