Point E will be on the same vertical line (x = n) as point D. So, the distance between points D and E will be the difference of their y-values:
2 - (-2) = 4 . . . units from D to E
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Points C and D appear to be on the same horizontal line (y = -2), The distance between them is the same as the distance between D and E (4 units). So, the distance between C and D will be the difference of x-coordinates:
