Category: Mini Lesson Plans

How Eratosthenes found the circumference of the Earth

Eratosthenes of Cyrene (b. c. 276 BC, Cyrene, Libya–d. c. 194, Alexandria, Egypt), Greek scientific writer, astronomer, and poet, the first man known to have calculated the Earth’s circumference. At Syene (now Aswan), some 800 km (500 miles) southeast of Read More