Question

Explain how the formula for getting the area of the circle was derived

Answer 1

One way is to inscribe a regular polygon of \(n\) sides and calculate the polygon area

As \(n -> \infty\), the area of polygon equals the area of circle

Answer 2

https://www.youtube.com/watch?v=YokKp3pwVFc

Answer 3

http://en.wikipedia.org/wiki/Area_of_a_disk

/thread

Answer 4

If I did this right
we at least know the area of the circle is between 2r^2 and 4r^2
and we know pi is between 2 and 4
I know this doesn't exactly derive the formula
but it estimates it
by the way I found that one length using Pythagorean theorem