When, where, and how did Eratosthenes determine the diameter and circumference of the Earth?

Question

I need this for a school assignment. I need the answer before 7:45 A.M 9-26-07(USA Texas).No jokes plz, thank you.

and why did Eratosthenes determin the diameter and circumference of the Earth?

answer the question the way a kindergartener could understand it NO JOKES PLZ!

Answer 1

The Earth's circumference was first determined around 240 BC by Eratosthenes. Eratosthenes knew that in Syene, in Egypt, the Sun was directly overhead at the summer solstice, while he estimated that a shadow cast by the Sun at Alexandria was 1/50th of a circle. He estimated the distance from Syene to Alexandria as 5,000 stades, and estimated the Earth's circumference was 250,000 stades and a degree was 700 stades (implying a circumference of 252,000 stades).[9] Eratosthenes used rough estimates and round numbers, but depending on the length of the stadion, his result is within a margin of between 2% and 20% of the actual circumference, 40,008 kilometres. Note that Eratosthenes could only measure the circumference of the Earth by assuming that the distance to the Sun is so great that the rays of sunlight are essentially parallel.

Answer 2

I advise first which you walk out of your place all alongside the Earth, following what we call a meridian and you will see you're lower back domicile after few years of walking and older already.You''ll word which you in no way felt into the unknown universe after achieving the top of a flat Earth. Secondly, purely have a seem to all the obtainable pictures taken via an incredible variety of satellites, human have sent into heaven and you will see the Earth is easily a sphere and not a flat piece of land.