Question 1135744
{{{drawing(400,4800/11,-5,6,-5,7, grid(1),
circle(-2,2,.1),circle(4,5,.1),circle(3,0,.1),circle(-3,-3,.1),
line(-3,-3,-2,2),line(4,5,-2,2),line(3,0,4,5),line(-3,-3,3,0),
green(line(-3,-3,4,5),line(3,0,-2,2))
 )}}}
<pre>Draw the quadrilateral and the diagonals on graph paper, and you 
can look and see that the midpoint of the two diagonals is the point
{{{(matrix(1,3,1/2,",",1))}}}.  You can work it out using the midpoint formula.

Edwin</pre