why do you think earth is round?
Answers
1. Watch a ship sail off to sea
Without being in the sky, it is impossible to see the curvature of the Earth. However, you can always see a demonstration of this if you visit a harbor or any place with a wide-open view of the water.
If you are able to watch a ship sail off to sea, watch its mast and flag as it fades off into the distance. You will notice that, in fact, it does not "fade off into the distance" at all; instead, you will see its mast and flag appear to slowly sink. The ship sailed beyond the point at which you would see it. Just to be sure, bring a pair of binoculars with you so that you can see even farther off into the distance.
It's as if you're watching it go over to the other side of a hill. This phenomenon can only be explained by a sphere-shaped planet.
2. Watch a lunar eclipse
Solar eclipses get all the attention, but if you are able to catch a glimpse of a lunar eclipse, you can see evidence that the Earth is, indeed, round. Here's how it works: Earth passes between the moon and sun, so that the sun projects Earth’s shadow onto the Moon in the night sky. You've probably seen a partial lunar eclipse without even noticing it; if the moon looks orange, that's a sign of a lunar eclipse. If you've ever seen a total lunar eclipse, you probably noticed that the shadow did not look like this.
Don't go by fool's errand the shape of earth is neither round nor sphere as stated above it is oblate spheroid