Answers:
These values are approximate
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Explanation:
The circumference formula is
C = 2*pi*r
which rearranges to
r = C/(2pi)
when solving for r.
Plug in the given circumference to find that
r = C/(2pi)
r = (39,750)/(2pi)
r = 6,326.40898790283
For the sake of the most accuracy possible, I'm using my calculator's stored version of pi (and not something like pi = 3.14); if your teacher requires you to use pi = 3.14 then follow those instructions of course.
The radius is roughly 6326 km when rounded to the nearest integer.
Keep in mind that the earth isn't a perfect sphere, but rather a slightly squished one. This means the earth is slightly fatter than it is tall. However, for the sake of this problem, we'll assume it's a sphere.
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Once you determine the circumference, aka distance around the circle, we can figure out the next problem: determining the distance from the north pole to the equator. This distance runs along a line of longitude, so it's a north-south distance.
Again, imagine the earth is a perfect sphere. This means that the equator circumference is the same as the circumference as a full longitude line when we travel the globe only along that line. In other words, start at the north pole, travel along that specific longitude only until you reach the south pole. Then staying on that line, travel back to the north pole going around the backend of the earth.
That full circular path we traveled will get cut into 1/4 because 1/2 the circumference is the portion from north to south pole, and then we cut that distance in half when going from north pole to the equator.
(1/4)*(6,326.40898790283) = 1,581.6022469757
That rounds to 1582 km
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Side notes:
