Answer:
Midpoint: (0, 5/2) or (0, 2.5)
Explanation:
The diagonal BD is made of the points B(4,7) and D(-4,-2)
to find the midpoint of these points you add the two x coordinates and divide by two --> (4+-4)/2=0/2=0
Then you add the y coordinates and divide by 2 --> (7+-2)/2=5/2 or 2.5
Then you've got your midpoint.
hopefully I've understood the question correctly - hope this helps!