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#1 2017-09-13 06:56:37

taylorn5683
Member
Registered: 2017-02-01
Posts: 10

Circumferences and Arc Length

What is the circumference of the circle if the radius is:


4. 3x-4
I tried and tired and there are no like terms so it wont work but my teacher says differant.



What is the radius if the circumference is:

6.  30x(pi)

radius is 4.8x


7. 4x-10pi
4x-31.4


8. (5/2)pi

1.24 Pi

9. 14pi
the radius is 2.2


10. (x + y)pi

  PI  x+PI y


she won't explain what is wrong or how to do it she says just use formula but I am confused with the variable I think.

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#2 2017-09-13 08:10:06

zetafunc
Moderator
Registered: 2014-05-21
Posts: 2,432
Website

Re: Circumferences and Arc Length

Hi taylorn5683,

Let's start with the formula for the circumference of a circle. If a circle has radius
, then its circumference is
. So, if a circle has radius
, then it has circumference
.

So if a circle has radius
, what must the circumference be?

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