Question

how was it proved that the earth is spherical in shape​

Answer 1

Answer:

Spherical Earth or Earth's curvature refers to the approximation of figure of the Earth as a sphere. The earliest documented mention of the concept dates from around the 5th century BC, when it appears in the writings of Greek philosophers.[1][2] In the 3rd century BC, Hellenistic astronomy established the roughly spherical shape of the Earth as a physical fact and calculated the Earth's circumference. This knowledge was gradually adopted throughout the Old World during Late Antiquity and the Middle Ages.[3][4][5][6] A practical demonstration of Earth's sphericity was achieved by Ferdinand Magellan and Juan Sebastián Elcano's circumnavigation (1519–1522).

Answer 2

After Galileo Galilei invented telescope all the other heavenly bodies were observed to be spherical in shape. So it was assumed that the Earth is also spherical in shape. This assumption was proved to be correct by sea exploration with the help of ships