Eratosthenes supposedly paid a man to walk from Alexandria to Syene, who then estimated the distance to be about 5000 stadia.  The shadow at Alexandria was measured to correspond to an angle of nearly 7 ¹/5°.

1. What is the degree measure for angle θ?  _____°
   
   
2. Use the information above, as did Eratosthenes, to calculate an estimate (in stadia) for the Circumference of the Earth.

    

3. If one stadion is approx. equal to 600 feet. convert your answer above to miles, rounding to the nearest hundred.

    

    

4. Determine the relative (%) error in Eratosthenes' estimate of the Earth's Circumference.