The "polar radius" is the distance between the centre of the Earth (or the planet you consider) and the poles.Insvims wrote:And what is a polar radius? The poles are just pinpoints, and can't have much radius. And these tracks don't have much differences.
The "equatorial radius" is the distance between the centre and a point on the equator.
It is always bigger than the polar radius, because of the rotation of the Earth (or the planet you consider).