1. ## The Circle

A few questions about the circle.

1. Is the circumference the perimeter of a circle?
2. Why is pi part of the formula C = pi•d?
3. Can we say that C = pi•d is the same as
C= (22/7)(d)?
4. The area of a circle is given by A = pi•r^2. Can this formula also be expressed as C = pi•(d/2)^2, where d is the diameter?

2. ## Re: The Circle

Originally Posted by harpazo
A few questions about the circle.

1. Is the circumference the perimeter of a circle?
2. Why is pi part of the formula C = pi•d?
3. Can we say that C = pi•d is the same as
C= (22/7)(d)?
4. The area of a circle is given by A = pi•r^2. Can this formula also be expressed as C = pi•(d/2)^2, where d is the diameter?
1. Yes.

2. As far as I know it is the original definition for the number $\displaystyle \pi$.

3. $\displaystyle \pi$ is only approximately 22/7. The correct expression uses $\displaystyle \pi$.

4. Don't you mean $\displaystyle A = \pi \left ( \dfrac{d}{2} \right ) ^2$

I don't want to discourage you from your studies but, really, you can look up all of these.

-Dan

3. ## Re: The Circle

Originally Posted by topsquark
1. Yes.

2. As far as I know it is the original definition for the number $\displaystyle \pi$.

3. $\displaystyle \pi$ is only approximately 22/7. The correct expression uses $\displaystyle \pi$.

4. Don't you mean $\displaystyle A = \pi \left ( \dfrac{d}{2} \right ) ^2$

I don't want to discourage you from your studies but, really, you can look up all of these.

-Dan
1. I am doing a self-study of math. My formal CUNY student days ended in 1993.

2. Yes, I meant A = pi(d/2)^2.

3. I know the basics of geometry. Of course, not at your level of comprehension but enough to pass an introductory middle school or high school geometry classroom test.

4. ## Re: The Circle

Originally Posted by harpazo
1. I am doing a self-study of math. My formal CUNY student days ended in 1993.

2. Yes, I meant A = pi(d/2)^2.

3. I know the basics of geometry. Of course, not at your level of comprehension but enough to pass an introductory middle school or high school geometry classroom test.
I'm aware of all this. However you need to also be working on your ability to handle the basics on your own. And by basics I'm referring here to basic definitions. All of this can probably be found on Wikipedia. If you are merely looking for a double check, then fine. But work on your self-confidence a bit.

-Dan

5. ## Re: The Circle

Originally Posted by topsquark
I'm aware of all this. However you need to also be working on your ability to handle the basics on your own. And by basics I'm referring here to basic definitions. All of this can probably be found on Wikipedia. If you are merely looking for a double check, then fine. But work on your self-confidence a bit.

-Dan
I find Wikipedia to be a bit mathematical. I prefer mathisfun.com or mathbits.com in terms of basic definitions. Dan, keep in mind that I am at the level of "Math For Dummies" considering that my last formal classroom experience took place in the Fall semester of 1993.

6. ## Re: The Circle

Originally Posted by harpazo
I find Wikipedia to be a bit mathematical. I prefer mathisfun.com or mathbits.com in terms of basic definitions. Dan, keep in mind that I am at the level of "Math For Dummies" considering that my last formal classroom experience took place in the Fall semester of 1993.
I simply mentioned Wiki because that's one of my own occasional sources. Wherever you find the material is good.

-Dan

7. ## Re: The Circle

Originally Posted by topsquark
I simply mentioned Wiki because that's one of my own occasional sources. Wherever you find the material is good.

-Dan
Do you also contribute to Wikipedia?

8. ## Re: The Circle

Originally Posted by harpazo
Do you also contribute to Wikipedia?
No. I prefer to do things like the Fora.

-Dan

9. ## Re: The Circle

Originally Posted by topsquark
No. I prefer to do things like the Fora.

-Dan
forae?

10. ## Re: The Circle

Originally Posted by romsek
forae?
Fora is as far as my Latin goes.

Carpe Michelobum!

-Dan

11. ## Re: The Circle

Sorry Dan...had a moment of weakness

12. ## Re: The Circle

Originally Posted by DenisB

Sorry Dan...had a moment of weakness
No comment on the topic, but I'm a musician. I made it through 45 seconds of that.... thing.

And it's stuck in my head. Thank you. Thank you very much.

-Dan

13. ## Re: The Circle

Originally Posted by topsquark
No comment on the topic, but I'm a musician. I made it through 45 seconds of that.... thing.

And it's stuck in my head. Thank you. Thank you very much.

-Dan
As a musician this juxtaposition made me cry laughing...

first for real

absolutely gorgeous

now for laughs

and she thinks she's just nailing it...

14. ## Re: The Circle

Originally Posted by romsek
As a musician this juxtaposition made me cry laughing...

first for real

absolutely gorgeous
I agree!

Originally Posted by romsek
now for laughs

and she thinks she's just nailing it...
This one reminds me of the Devil's turn in "The Devil Went Down to Georgia."

-Dan

15. ## Re: The Circle

Originally Posted by topsquark
No. I prefer to do things like the Fora.

-Dan
What is Fora?

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