Flattening

The flattening, ellipticity, or oblateness of an oblate spheroid is the "squashing" of the spheroid's pole, down towards its equator.

Flattening Media

• An ellipse with auxiliary circle.svg

  A circle of radius a compressed to an ellipse.

• Ellipsoid revolution oblate aab auxiliary sphere.svg

  A sphere of radius a compressed to an oblate ellipsoid of revolution.