What did erosthothenes do?

Answer 1

Eratosthenes was an ancient Greek mathematician, astronomer, and geographer known for calculating the Earth's circumference with remarkable accuracy around 240 BC. He used the angle of shadows cast by obelisks in different locations to estimate the Earth's size, determining it to be about 39,375 kilometers (24,662 miles). Additionally, he is credited with creating one of the earliest maps of the known world and developing the first known algorithm for finding prime numbers, known as the Sieve of Eratosthenes. His work laid foundational principles in geography and mathematics.