Subject: 71:11/7166 Math - area of a sphere
T::> I'm trying to determine the surface area of a hypothetical planetary bod
::>given the circumference of that body (assuming it is a pefect globe with no
::>blemishes or terrain). Does anyone know the formula for this? I'm working i
::>kilometers, and suck at math. Please reply directly. Thank you!
Let's start with the fundamentals. That circumference that you
have is equal to 2*pi*r (pi is that familiar constant,
approximated badly by the fractions 22/7 or 355/113). The area of
a sphere is 4*pi*r^2 (r^2 is "r squared", or r*r).
Now, (4*pi*r*r)/(2*pi*r)=2*r, which equals (2*pi*r)/pi. So, given
the circumference C, we can arrive at the surface area by using
the formula
C*C/pi.
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Jeff Zeitlin [email removed]
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~ QMPro 1.52 ~ That was profound! I didn't understand a word.