He used only simple geometry and observation of the sun
Eratosthenes assumed that the sun was so far from the earth that its rays were practically parallel when they reached it, and that the earth was spherical. Then, he calculated the the degree of elevation of the sun at Alexandria and Syene at specific times, and estimated the distance between the two. By so doing, he was able to calculate what he thought was the number of stadia per degree of elevation of the sun. Then, he multiplied this quantity by 360 degrees (the maximum elevation of the sun assuming that the earth was spherical) to calculate the circumference of the earth.
Eratosthenes discovered the approximate circumference of the Earth by measuring shadows at two locations in Egypt and using the difference in shadow lengths to calculate the Earth's curvature. By comparing this with the actual distance between the two locations, he was able to estimate the Earth's circumference with remarkable accuracy for his time.
Eratosthenes
Eratosthenes calculated the Earth's circumference by measuring shadows at two different locations at the same time. He then used the angles of the shadows cast by a vertical stick to calculate the Earth's circumference using geometry and trigonometry. By comparing the shadow angles at two different locations, Eratosthenes was able to estimate the Earth's size accurately.
Eratosthenes determined the size of the Earth by measuring the angle of the shadow cast by a vertical stick in two different locations on the same day. By comparing the angles at the two locations and knowing the distance between them, he was able to calculate the Earth's circumference.
Eratosthenes, a Greek astronomer and mathematician, used the difference in the Sun's position at noon on the summer solstice at Alexandria and Syene to estimate the Earth's circumference in the 3rd century BCE. By measuring the angles of shadows cast by sticks in the ground at each location, he calculated the Earth's circumference to be approximately 39,375 kilometers.
Eratosthenes determined the Earth's circumference by measuring the angle of the sun's rays at two different locations on the same meridian. By comparing the angles and the distance between the locations, he calculated the Earth's circumference with remarkable accuracy for his time.
Which of the following describes how Eratosthenes discovered the approximate circumference of the earth
He did not do so. Earth was well-known to be a globe for at least two hundred years before Eratosthenes' time. What Eratosthenes did was to measure the earth's circumference for the first time. He did that at some time between 236 BC and 195 BC.
Eratosthenes
Eratosthenes
He postulated the circumference of the earth.
rome
Eratosthenes
Eratosthenes
Eratosthenes
he wanted to find the circumference of the earth.
Both postulated on the earth's circumference.
I believe that would be the Earth.