Size and Shape of the Earth - SS1 Geography Lesson Note

The Earth is an oblate spheroid, which means it is mostly spherical but slightly flattened at the poles and bulging at the equator. Its approximate characteristics are:

Diameter: About 12,742 kilometers (7,918 miles).

Circumference: Roughly 40,075 kilometers (24,901 miles) around the equator.

Surface Area: Approximately 510.1 million square kilometers (196.9 million square miles).

Source:(flickr.com)

The Earth's shape is due to its rotation, which causes a slight flattening at the poles and bulging at the equator. It's not a perfect sphere but very close to one.