Why is the Earth not an ideal ball?

The earth rotates around its axis. As a result, centrifugal forces arise. Therefore, the globe is slightly flattened at the poles.
Firstly, it has an uneven surface
Secondly, because of its rotation, our planet is slightly flattened at the poles: the distance from the center of the Earth to the equator is 6378 km, and to the poles – 6356 km

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