The greek mathematician eratosthenes (ca. 276-195 bc) measured the circumference of the earthfrom the following observations. he noticed that on a certain day the sun shone directly down a deep wellin syene (modern aswan). at the same time in alexandrea, 500 miles north (on the same meridian), therays of the sun shone at an angle of 7.2° to the zenith. use this information to find theradius and circumference of the earth.

Radius of the Earth is 3978.8 Miles

Circumference of the Earth is 25000 Miles

Step-by-step explanation:

The angle of the sun shone at an angle of 7.2° to the zenith

This means that the angle of the sector of the circle is 7.2° (θ)

S = Length of the sector of the circle = 500 miles

r = radius of earth

Converting 7.2° to radians

∴ Radius of the Earth is 3978.8 Miles

∴ Circumference of the Earth is 25000 Miles

step-by-step explanation:

answer is because 4×10=40

and 98×4= is 392

40,392