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Originally Posted by footfootfoot
Seems like there is more surface than that.
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Surface area of a sphere: 4 * pi * r * r
r = 3978
3978 * 3978 * 3.1416 * 4 = SA of Earth
198,856,795 approx surface area of Earth.
r = radius = diameter / 2
c = circumference = 25,000 miles
circumference of Earth approx 25,000 miles
radius of Earth approx 3978 miles
c / d = pi
25000 / d = 3.1416
25000 = 3.1416 * d
25000 / 3.1416 = d
7958 miles = d
d = 2r
7958 = 2r
7958 / 2 = r
3978 = r
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Originally Posted by cribbed from some math site cause I forgot the formula
The distance around a circle is called the circumference. The distance across a circle through the center is called the diameter. Pi is the ratio of the circumference of a circle to the diameter. Thus, for any circle, if you divide the circumference by the diameter, you get a value close to Pi. This relationship is expressed in the following formula:
C over d equals Pi
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