10 A circle has equation \(x ^ { 2 } + y ^ { 2 } + 2 x - 4 y - 8 = 0\).
- Find the centre and radius of the circle.
- The circle passes through the point \(( - 3 , k )\), where \(k < 0\). Find the value of \(k\).
- Find the coordinates of the points where the circle meets the line with equation \(x + y = 6\).