The difference between the longest and shortest diameters is 44
kilometers (27 miles), and that means that the "oblateness" of the
earth (its departure from true sphericity) is 44/12755, or
-0.0034. This amounts to l/3 of 1 percent.
+0.0034. This amounts to 1/3 of 1 percent.
To put it another way, on a flat surface, curvature is 0 per mile
everywhere. On the earth's spherical surface, curvature is 0.000126