9
\includegraphics[max width=\textwidth, alt={}, center]{3fd0b68f-41b1-4eee-8018-bcaf3cf22950-4_767_993_255_575} The diagram shows a quadrilateral \(A B C D\) in which the point \(A\) is ( \(- 1 , - 1\) ), the point \(B\) is ( 3,6 ) and the point \(C\) is (9,4). The diagonals \(A C\) and \(B D\) intersect at \(M\). Angle \(B M A = 90 ^ { \circ }\) and \(B M = M D\). Calculate

1. the coordinates of \(M\) and \(D\),
2. the ratio \(A M : M C\).