The Earth is oblate spheroid (bulging at equators and flattening at poles) in shape. However, in the early days it was thought to be a flat piece of land. A major discovery with respect to the circumference and shape of the Earth was done in 25 BC. A Greek mathematician, named Eratosthenes, calculated the circumference of the Earth using the idea of a round shape. The diameter of the Earth is about 12,714 km, and the Earth bulges at the equator. Sir Isaac Newton carried out the analysis related to the bulges of the Earth at the equator, for the first time.
Shape of the Earth
