## anonymous one year ago Help.. I need details to help me understand.

1. anonymous

substitute 37.7 meters instead of C. What do you get?

2. anonymous

$\frac{ c }{ 2\pi } = r$ where C is your circumference

3. anonymous

I'm confused

4. Vocaloid

5. Vocaloid

37.7 = 2πr now solve for r

6. anonymous

i dont know how to do this

7. Vocaloid

divide both sides by 2π

8. anonymous

... how do you divide that the π confuses me

9. Vocaloid

π is just a number, it's equal to about 3.14

10. Vocaloid

you know how to divide 37.7 by 2, right? you also know how to divide 37.7 by 3.14, right? just do both at the same time

11. anonymous

18.85? & I'm unsure how to divide the second one ?

12. Vocaloid

18.85/3.14 = ? (use a calculator)

13. anonymous

$\frac{ 37.7 }{ 6.2831 }$

14. anonymous

it gives me a big number

15. anonymous

I'm clearly horrible at math

16. anonymous

$\frac{ 37.7 }{ 2*3.14.159 }$

17. anonymous

err seems I added 1 to many . there... but that will give you your r value

18. Vocaloid

enter "37.7", then press the divide button, then enter "6.2831", then press the enterbutton/equal sign

19. anonymous

it should be #.xxxxxxxxx but you can ignore the xxxxxxx part as they are mostly 0

20. Vocaloid

or just use an online calculator https://www.bing.com/search?q=37.7%2F6.2831&PC=U316&FORM=CHROMN

21. anonymous

6.0002228199455698 ?

22. anonymous

yes

23. Vocaloid

24. anonymous

but 6 will do

25. anonymous

okay? still kind of lost

26. Vocaloid

you're done, you just found that the radius is equal to 6

27. anonymous

I'm just a little confused how we got there lol

28. anonymous

the formula you were given was C = 2πr

29. anonymous

using algebra we moved our variables around to solve for r since C was given. We divided 2π from both sides like so C/2π = 2πr/2π the 2π on the side of 2πr cancelled leaving us with C/2π = r and from there you just plugged in values C = 37.7 and 2*(3.1415) which is the value of π

30. anonymous

hope that helps :)

31. anonymous

i think i'm dumb cause i dont get it lol

32. Vocaloid

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33. Vocaloid

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34. Vocaloid

do you understand this part?

35. anonymous

yes

36. Vocaloid

good, now the problem says that the circumference is 37.7, so we replace "C" with 37.7 do you understand that part?

37. anonymous

yes

38. Vocaloid

good, now we want to find the radius

39. Vocaloid

so we want r by itself on the other side

40. Vocaloid

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41. Vocaloid

do you understand that part?

42. anonymous

yeah

43. anonymous

it's making more sense

44. Vocaloid

good, so r = C/(2π) = 6

45. anonymous

$\frac{ 1 }{ 2π } * C = 2πr * \frac{ 1 }{2π} \rightarrow r = \frac{ C }{ 2π }$

46. anonymous

heh guess I should have made a picture :)

47. anonymous

I GET IT NOW!