from what i understand the circle has a fixed circumference of about 3 meters

how is that possible when you can draw smaller and bigger ones how can the circumference not change according the size you draw?

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- Aug 18th 2012, 10:31 AMariel32circumference of the circle
from what i understand the circle has a fixed circumference of about 3 meters

how is that possible when you can draw smaller and bigger ones how can the circumference not change according the size you draw? - Aug 18th 2012, 10:59 AMearbothRe: circumference of the circle
Maybe you've misunderstood something ...

The cirumference of a circle is calculated by $\displaystyle p = \pi \cdot d$, where p means perimeter and d is the diameter of the circle.

Rearranging this equation you'll get $\displaystyle \frac pd = \pi \approx 3.14159$

So maybe you've heard that the**ratio**of these 2 lengthes is a fixed value of nearly 3. - Aug 18th 2012, 11:03 AMHallsofIvyRe: circumference of the circle
I have no clue what you are talking about. "from what i understand the circle has a fixed circumference of about 3 meters"???

**What**circle are you talking about? Surely you don't mean "the circle" in the sense of "all circles". Every circle has circumference proportional to its diameter, NOT "fixed". The circumference of a circle is $\displaystyle \pi$**times**its diameter. Now $\displaystyle \pi$ is a constant slightly larger than 3 so every circle has circumference "about 3" (but NOT "3**meters**") times the diameter of circle. Perhaps $\displaystyle \pi$ is the "about 3" you are thinking of. But, again, $\displaystyle \pi$ is a number, not a measurement, and so has no units such as "meters". And the circumference is that number**times**the diameter of the circle.

A circle of diameter 1 mm has circumference about 3.14 mm. A circle of diameter 1 light year has circumference about 3.14 light years. Neither of those is anywhere near "3 meters".