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

[Panic]

??? 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

[ed84c]

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.........

[mike12345]

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

 

=======================

 

mike5

 

WideCircles

[ajb]

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 ([math]A[/math]) is given by

 

[math]A = \pi r^{2}[/math]

 

where [math]r[/math] is the radius.

 

So given the area we know the radius, true.

 

(Why we bringing this thread alive again?)