Eratosthenes lived in Alexandria of Egypt in BC 240.. He found out the diameter of Earth thorough geometry and mathematics. Hope this helps .. :)
Well it depends on multiple things like the climate, amount of precipitation and so on like in a desert its gonna be hard to have run off because the water will just soak into the ground through its cracks because it doesn't get sufficient water supply. hope this helps.
Members of Congress) Sorry have to type more it will not let me post ok this should do it, have a great rest of your day.
