However, you do not appear to have X Y coordinates. If what you have is a polyhedra that is 102.49728 in one direction, 126.68069 in a second direction, 127.49728 in a third direction, and so on, then prod() the array.
However I am guessing you want
p = [102.49728 126.58069 127.49728 126.58069 127.49728 163.58069 102.49728 163.58069];
xy = reshape(p, 2, ).';
and then you could polyarea() on xy(:,1) and xy(:,2)