The way I see it is the shadow of the Earth that makes the moon into a crescent shape in the sky is always rounded and never has any edges on it. The sun is round and the planet's are all round and never have any flat edges, even the dwarf planet Ceres has crushed itself into a spherical shape. Every person on Earth has a different scope of the sky, if the Earth was flat then everyone on earth would see the same stars in the sky every night but they don't. If the Earth was flat then gravity would not be the same throughout the Earth because the middle of the Earth would have more mass and people on the edges would be pulled sideways slightly. There are people in the international space station going around the globe in orbit and can see the Earth is a round sphere.
Just saying. I try to keep an open mind but I will call this case closed and keep my verdict. Don't be angry with me peeps.