well, a parallelogram is a four-sided figure with opposite sides parallel. a rectangle is a figure with four straight sides and four right angles, and two of those sides are adjacent and unequal so, in short, all rectangles are parrolegrams but not all parrolelograms are rectangles. the answer would be: yes, it is possible.
centre = (2, 6)
the centre is at the midpoint of the diameter.
use the midpoint formula to find the centre
centre = [(- 2 + 6), (8 + 4)] = (2, 6)