How did Eratosthenes estimate the size of Earth in 240 B. C.?

a. By sending fleets of ships around Earth
b. by comparing the maximum altitude of the Sun in two cities at different latitudes
c. by observing the duration of a solar eclipse by measuring the size of Earth's shadow on the Moon in a lunar eclipse.
d. We don't know how he did it since all his writings were destroyed.

Eratosthenes estimate the size of Earth in 240 B.C. by comparing the maximum altitude of the Sun in two cities at different latitudes.

Therefore we can conclude that Eratosthenes estimate the size of Earth by comparing the maximum altitude of the Sun.

Thus option B. is the correct answer.

Learn more about " Eratosthenes" here:

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The correct answer is letter C

Eratosthenes of Cyrene was an important pre-Socratic geographer, mathematician, astronomer and philosopher. He is considered the father of Geography in Antiquity, due to the important studies on the measurements of the Earth that he carried out. He was one of the leading scientists and thinkers in Ancient Greece.

oil! is what i am assuming