(a) The distance between Paris, France, and Rio de Janeiro, Brazil is 5717 miles. If lines were drawn from Paris and Rio to the center of the earth, those lines would meet at an angle of

Using this information, we can estimate that the radius of the earth is

(b) The distance between Moscow, Russia, and Istanbul, Turkey is 1105 miles.
If lines were drawn from Moscow and Istanbul to the center of the earth, those lines would meet at an angle of

Using this information, we can estimate that the radius of the earth is

Compare your two answers. Do you think this would be considered a good approximation? Why or why not?