Maths Fans - Pi

by **Raymond-Bergman** on Mon May 23, 2005 4:12 pm

Ok we all know that Pi is 3.142.....

But how did early maths bods know that the ratio of circumference to diameter was the same for all circles?

Its something thats puzzled me for a long time, anyone have a clue?

by **Guest** on Mon May 23, 2005 4:35 pm

By measuring it, painfully, making approximations, at least until trigonmetry came along and the ability to offer a proof.

Website · by **blobrana** on Mon May 23, 2005 4:48 pm

Hum,
perhaps its not always true.

It just might be that in our part of space that there is a bit left over when we divide a circle...

by **Guest** on Mon May 23, 2005 5:24 pm

that is the relationship between math and logic: proofs.

by **Buffyphile** on Mon May 23, 2005 8:55 pm

Due to the fact that all parts of the circumference are equidistant from the centre, otherwise it is not a circle but a polygon, there is a known change in all dimensions equally with the movement in the dimension of any dimension of the radius or circumference.

That is to say if you change the radii of the object in order to accommodate the change the circumference has to move away from the centre yet still remain intact so has to move by an equal proportion.

Pi itself is used as a measure to determine this proportional change as it can't be represented as a real number (3.142 is an approximation) to be accurate Pi goes to hundreds of decimal places but the number used will give a good enough result for most people.

by **427v8** on Mon May 23, 2005 9:32 pm

blobrana wrote:Hum,
perhaps its not always true.

It just might be that in our part of space that there is a bit left over when we divide a circle...

Well Pi is an Approximation...

A real simple approximation ( and not very good one) is to make a square with the sides equal to the circles diameter.

A better approx is to use a polygon with 1,000 sides....

an even better one is 100,000,000 sides

by **Chad05** on Mon May 23, 2005 11:06 pm

Buffyphile wrote:Due to the fact that all parts of the circumference are equidistant from the centre, otherwise it is not a circle but a polygon, there is a known change in all dimensions equally with the movement in the dimension of any dimension of the radius or circumference.

That is to say if you change the radii of the object in order to accommodate the change the circumference has to move away from the centre yet still remain intact so has to move by an equal proportion.

Pi itself is used as a measure to determine this proportional change as it can't be represented as a real number (3.142 is an approximation) to be accurate Pi goes to hundreds of decimal places but the number used will give a good enough result for most people.

Will that work in the USA as well?
Only i don't think we're on the same time as you are. :shock:

by **Tina TV** on Tue May 24, 2005 12:18 am

Chad05 wrote:Will that work in the USA as well?
Only i don't think we're on the same time as you are.

Oh don't confuse them. Pi is far to technical. They are still arguing over evolution after all.

by **long-leggedy-annie** on Tue May 24, 2005 8:52 am

Tina TV wrote:
Chad05 wrote:Will that work in the USA as well?
Only i don't think we're on the same time as you are.

Oh don't confuse them. Pi is far to technical. They are still arguing over evolution after all.

And they are happier eating pies, let alone using pi to work anything out!

by **Raymond-Bergman** on Tue May 24, 2005 8:46 pm

Tina TV wrote:Oh don't confuse them. Pi is far to technical. They are still arguing over evolution after all.

ooooOhh get Tina!

by **PooftersUnited** on Tue May 24, 2005 9:14 pm

Raymond-Bergman wrote:
Tina TV wrote:Oh don't confuse them. Pi is far to technical. They are still arguing over evolution after all.

ooooOhh get Tina!

HEY!

Stop picking on the TV, you beastly man :shock:

by **Buffyphile** on Tue May 24, 2005 10:23 pm

Chad05 wrote:
Will that work in the USA as well?
Only i don't think we're on the same time as you are.

Yes, just replace centre with center and it'll adjust for the time difference :lol:

by **Raymond-Bergman** on Tue May 24, 2005 10:23 pm

by **mostirreverent** on Wed May 25, 2005 5:00 am

is a circle not and a polygone whose sides are infinite in number. if so, then by definition, how can Pi be and approximation? if a monkey is on a cross, pi has something to do with his tail. all hail Jessie Helms and Jerry Falwell

good movie BTW.

by **Raymond-Bergman** on Wed May 25, 2005 4:59 pm

mostirreverent wrote:is a circle not and a polygone whose sides are infinite in number. if so, then by definition, how can Pi be and approximation? if a monkey is on a cross, pi has something to do with his tail. all hail Jessie Helms and Jerry Falwell

good movie BTW.

Wow two real rarities in this thread!

The solution to pi and a post from MI with no mention of Anal.

Its to be applauded!!

Maths Fans - Pi

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