## anonymous one year ago A bicycle wheel with radius 26" rotates through an arc that measures 80°. What is the length of the arc of the tire that touched the ground? a) 2.88pi inches b) 5.78pi inches c) 11.56pi inches

1. anonymous

I tried to divide 80 by 26 and then multiplying that answer by 180, but it didn't work out so well...

2. anonymous

now we have to convert 80 degree to radians

3. anonymous

Divide it by pi

4. anonymous

?

5. anonymous

no this time we are converting the other way $80\times \frac{\pi}{180}$

6. anonymous

1.395?

7. anonymous

that comes out to be $\frac{4\pi}{9}$ radians

8. anonymous

oh

9. anonymous

0.4pi

10. anonymous

yeah about that we are still not done though

11. anonymous

Do we multiply that by 180?

12. anonymous

no now we think, maybe draw a picture

13. anonymous

|dw:1436971051817:dw|

14. anonymous

we want $$a$$ the arc length the radian measure is arc length over the radius so $\frac{a}{26}=.4\pi=1.4$ so $a=26\times 1.4$

15. anonymous

http://www.wolframalpha.com/input/?i=26*1.4 you got a choice that is close to 36.4?

16. anonymous

oh wait, i see all your answers have $$\pi$$ in them

17. anonymous

$a=26\times \frac{9}{4}\pi=11.5\pi$

18. anonymous

Wow that makes alot more sense than it did before

19. anonymous

yeah sorry i messed up earlier

20. anonymous

Umm. There's another question. I have already answered it, but I want to make sure I'm doing this the right way

21. anonymous

kk

22. anonymous

If the length of an arc is 12pi inches and the radius of the circle is 10 inches, what is the measure of the arc? a) 216 degrees b) 270 degrees c) 288 degrees

23. anonymous

I chose A

24. anonymous

Is that correct?

25. anonymous

let me check

26. anonymous

the radian measure is $\frac{12\pi}{10}=1.2\pi$

27. anonymous

then $1.2\pi\times \frac{180}{\pi}=1.2\times 180=216$

28. anonymous

yeah you got it !

29. anonymous

Thanks

30. anonymous

31. anonymous

I feel pretty good now. Finally! Lol!

32. anonymous

33. anonymous

what should i be looking for ?>

34. anonymous

Me dropping my music and then picking it up on the left side of the screen somewhere in the middle of the song

35. anonymous

Lol!

36. anonymous

I should be the last person on the row of trumpets. On the outside since I'm leader

37. anonymous

i will look again right or left side?

38. anonymous

Left

39. anonymous

You should see white paper

40. anonymous

on the floor and me picking it up

41. anonymous

ok looking now

42. anonymous

You see it. I mean me Lol!

43. anonymous

lol yeah

44. anonymous

you are hidden mostly but i did see you pick up the sheet!

45. anonymous

Yeah It's a little embarrassing

46. anonymous

you got more math questions are are you ok? i gotta run soon

47. anonymous

Oh sorry

48. anonymous

I had to grab something to eat

49. anonymous

eating is good you got any more before i run?

50. anonymous

Yeah