The fact is the Earth is round. They are multiples ways of telling this both physical and mathematically. Physically if you take a rocket and launch it and have it take pictures you will see a picture of a green and blue color sphere that is fairly big. Though from what I have seen most flat earth believers that NASA and satellites are a huge conspiracy. Know there are other physical ways to tell that the earth is round. If you observe a ship that is moving away from you, it appears that the ship is sinking below the horizon that's because the earth has a curve every 23 miles. If the earth is flat, then the ship would stay level. Also many people have flown around the earth, including Steve Fossett for flying a hot air balloon around the world starting and ending in Australia. Now mathematically when a lunar eclipse happens it cast a shadow on the moon. If you look at each shadow you see that the are varied in length from one to another. If the earth was flat, then you will see that the length between the shadows are identical and their not identical. Hopefully you will see that the earth is round and if not, provide evidence like this that could actually convince a person.