+14985 how to calculate parimetre of a circle
area A
radius r
diameter d
circumference C
\(C=d\pi\)
\(C=2\pi r\)
\(C=\sqrt{4\pi A}\)
\(A=\pi r^2\)
\(A=\frac{d^2 \pi}{4}\)
\(A= \frac{C^2}{4\pi}\)
\(r=\frac{C}{2\pi}\)
\(r=\sqrt{\frac{A}{\pi}}\)
\(r= \frac{d}{2}\)
\(d= \frac{C}{\pi}\)
\(d=\sqrt{ \frac{4A}{\pi}}\)
\(d=2r\)
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