EARTH — Our planet's shape can be verified in many ways.
Disclaimer: We can't promise these facts will convince flat-earthers. But hey, it's worth the shot … right?
Earth's globe-like shape can be easily observed in the shadow it casts on the moon's equally round surface. The shadow is always curved at any given time of the lunar phases.
Earth's round edges can also be seen in the horizon. Objects nearing it seem to "appear" and "disappear," depending on which way they are moving. We can see this effect when we observe ships in the ocean. If we were to see the horizon from above, we would also be able to see Earth's surface curve at the edges.
Earth's circular form also determines the time zone differences we experience. Time zones are a result of Earth's rotation on its axis.
Its spherical shape allows for this as its sides would be exposed to sunlight at a given time while the other side remains dark. This would not be possible over a flat surface.
We can also observe the properties of other planets in our solar system. According to Futurism, planets' spherical shapes allow for an equal distribution of gravity.
If Earth were a disc-like body, its gravity would pull us at different degrees depending where we stand. Gravity cannot be distributed evenly on non-spherical surfaces.