Question

12 how did eratosthenes calculate the circumference and tilt of the earth? eratosthenes studied the night sky and the apparent movement of the stars to calculate the circumference and tilt of the earth. eratosthenes measured the amount of time it took for the earth to rotate once on its axis and compared it to earths alignment with the moon and the stars. eratosthenes measured the distance from the earth to the moon to determine the circumference and tilt of the earth. eratosthenes calculated the circumference and tilt of the earth by measuring the angle of the suns rays and the distance between locations.

Explanation:

Eratosthenes calculated the Earth's circumference by measuring the angle of the sun's rays at two different locations (Syene and Alexandria). He knew the distance between these locations. Using basic geometry and the proportion of the angle to a full - circle (360 degrees), he was able to estimate the Earth's circumference. He did not measure the tilt of the Earth in this experiment, nor did he use the Earth - moon distance or study the night sky in this particular calculation of the Earth's circumference.

Answer:

Eratosthenes calculated the circumference of the Earth by measuring the angle of the sun's rays and the distance between locations.