6 Three points, \(A , B\) and \(C\), are such that \(B\) is the mid-point of \(A C\). The coordinates of \(A\) are ( \(2 , m\) ) and the coordinates of \(B\) are \(( n , - 6 )\), where \(m\) and \(n\) are constants.
- Find the coordinates of \(C\) in terms of \(m\) and \(n\).
The line \(y = x + 1\) passes through \(C\) and is perpendicular to \(A B\).
- Find the values of \(m\) and \(n\).