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How do you get the area of a circle and why is it like that?
(NOT HOMEWORK!!!!!)

2006-11-23 18:10:14 · 20 answers · asked by pokemon_jirachi555 1 in Science & Mathematics Geography

20 answers

Sigh - first guy had it right, but didn't explain it all.
Pi = 3.14- all you need for the problem
Radius= half the diameter of your circle. You find the midpoint and measure from there to the side of the circle, in any direction. Most problems give you the radius. or at least show you the midpoint on the circle.

So, it is 3.14 x the amount of the radius x 2= the area of the circle.

You can do this in reverse as well, if you know the area but not the radius.

2006-11-23 18:21:29 · answer #1 · answered by Anonymous · 1 0

First? Do you know what the radius of a circle is? The radius is the "Distance from the center of a circle to a point on the circle". To find the area of a circle you must multiply the radius, squared, to pi, which usually is 3.14.
The reason for this? I'm not sure about that. It is just that way, and for all of us who do have homework, sadly have to deal with that. I know...math is not the funnest subject in the world. I hope this helped.

2006-11-23 18:35:54 · answer #2 · answered by *Balanced*Sweetheart*Always* 2 · 1 1

You know about the value "pi" right? (Don't want to take the time to make the symbol). If not, it is approximately 3.1416....All you do is multiply "pi" by the square of the radius. Ex: for a circle with a radius of 5 (inches, feet, meters, doesn't matter), then the area would be pi times 25 (five squared), or approx. 78 square units....OK? Glad to help.

2006-11-23 18:16:25 · answer #3 · answered by Yinzer Power 6 · 2 0

Formula of Area of a Circle = Pie x Radius x Radius

Pie = 3.14159 (It will be provided, so don't need to find out the actual value, but it can be better if you can remember it)

Radius = Diameter divide 2
(If Radius is not given, use the Diameter value to divide by 2)
(However if Radius is provided, just use the value directly)


Hope that helps you out.

2006-11-23 18:20:12 · answer #4 · answered by PoshBerries 6 · 0 0

Hi Poke, All i know is take a pencil and draw a round circle. Not good in this kind of math. At least i answer. Have a good night.

Clowmy

2006-11-23 18:18:50 · answer #5 · answered by Anonymous · 0 0

r =radius
area of circle =pi (22/7 -fractional value of pi) x r x r
=pi multiplied by radius square

2006-11-23 22:12:51 · answer #6 · answered by cool 2 · 0 0

Area of circle is pi * (radius)^2.
Diameter of circle is 2 pi (radius).

As you may have noticed, diameter is the differential of area.

2006-11-23 18:14:03 · answer #7 · answered by notscientific 2 · 1 0

I used to get confused between the 2 formulae:

2 pi x r and
pi x r 'squared'

the 'squared' one has to be about area, so the other one is to find the circumference.

2006-11-23 18:25:22 · answer #8 · answered by Bart S 7 · 0 1

pi*r^2=A

where
pi= 3.14159...
r=radius of circle
A=area of circle

it is like this because pi is the ratio that compare the squared value of a cirlce's radius to its area.

2006-11-23 18:13:59 · answer #9 · answered by Brian R 2 · 1 0

You mean why is it that irrational numbers do not have a real answer eg. Pi is 3.1415................ and the more powerful the computer the longer the answer but there is no end to it. Pi just goes on and on. Interesting question.

2006-11-24 02:49:18 · answer #10 · answered by compute_86 1 · 0 0

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