What is the ratio between the polar and equatorial radii of the Earth?

In order to answer this question, you need to know what the radius is. You also need to know about the structure of our planet.

The radius is the shortest distance from the center of the ball (in our case, planet Earth) to its surface.

It is also necessary to remember that our earth does not have the shape of a ball, as is commonly believed, but the shape of a geoid – a ball flattened to the poles.

Knowing this, we understand that the radius will not be the same at the equator and at the poles.

At the equator it will be 6378 kilometers, and at the poles 6356 kilometers. The difference is small, only 22 kilometers, but this is no longer a ball.

The ratio of the radii will be approximately 0.997.