6 The vertices of triangle \(A B C\) are \(A ( - 3,1 ) , B ( 5,0 )\) and \(C ( 9,7 )\).
- Show that \(A B = B C\).
- Show that angle \(A B C\) is not a right angle.
- Find the coordinates of the midpoint of \(A C\).
- Determine the equation of the line of symmetry of the triangle, giving your answer in the form \(p x + q y = r\), where \(p , q\) and \(r\) are integers to be determined.
- Write down an equation of the circle with centre \(A\) which passes through \(B\).
This circle intersects the line of symmetry of the triangle at \(B\) and at a second point.
- Find the coordinates of this second point.