# how do i work out the area of a circle without a calculator?

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??? what say you!!

that just gave me a head ache!

Or you could just

square the radius and multiply it by 3

approximately close enough ... give or take .142

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Never post again.

where u being sincere?

My suggestion, work it out in terms of pi.

Alternatively if you are allowed to use a computer for graphs; draw a graph of Cos-1 rsqrd * ®sqrd. Then read off the graph. Allthough unless its a special challenge, that requires lateral thinking.........

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By using this formula we can find the radius of circle.i.e,R=3.14*r*r.Same for area also.

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mike5

WideCircles

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By using this formula we can find the radius of circle.i.e,R=3.14*r*r.Same for area also.

You mean the area enclosed by a circle ($A$) is given by

$A = \pi r^{2}$

where $r$ is the radius.

So given the area we know the radius, true.

(Why we bringing this thread alive again?)