A person six feet tall walks around the earth. Assuming the earth is a perfect sphere, how many feet farther does the top of this person's head travel than the bottoms of his feet? Express your answer in terms of $\pi$.
Let the radius of the Earth = R feet
Then the circumference = 2pi*R = distance traveled by the person's feet
The top of the person's head tavels 2pi* (R + 6) feet
So.....the person's head travels [ 2pi ] [ (R + 6) - R ] = 2*pi *6 feet more =
12pi ft more
