Question

how can people come to an understanding that Earth is spherical​

Answer 1

⠀⠀ ⠀ ⠀⠀ $\huge{\tt{\red{❥}\green{A}\purple{N}\pink{S}\blue{W}\orange{E}\red{R}}}$The roughly spherical shape of the Earth can be confirmed by many different types of observation from ground level, aircraft, and spacecraft. The shape causes a number of phenomena that a flat Earth would not.

Answer 2

Answer:

When Ferdinand Magellan sailed across the world and reached the same place, it was proved that the earth is round.

Moreover, pictures taken by NASA are the latest proofs.

Elon Musk is working hard for commercial spaceflight so that common people like you and me can walk over the moon and see our earth from there.