Before revision: Approximating the figure of Earth by an Earth spheroid , the radius ranges from a maximum (equatorial radius, denoted a) of nearly to a minimum (polar radius, denoted b) of nearly .
After revision: (an oblate ellipsoid)Approximating the figure of Earth by an Earth spheroid , the radius ranges from a maximum (equatorial radius, denoted a) of nearly to a minimum (polar radius, denoted b) of nearly .