Question

How do people come to an understand that Earth is spherical

Answer 1

lunar eclipse
circum navigation
location of pole star
Bedford level experiment

Answer 2

ANSWER:

From the experiments done by Ferdinand Magellan, people come to an understanding that Earth is spherical.

EXPLANATION:

When the Earth comes in between the sun and the moon, Earth cast their own shadow on the moon, the shadow is spherical. The horizon near the ocean it seems that both are merged.

A traveler named Ferdinand Magellan started his journey from the west, came back from east. This proved that the earth is spherical. By the above experiments and observation, we can conclude that earth is spherical. If it had been flat the above experiments and observation would have been failed.