## anonymous one year ago ***WILL MEDAL*** Find the length of an arc of 40° in a circle with an 8 inch radius. a) 8pi/9 inches b) 16pi/9 inches c) 64pi/9 inches

1. anonymous

@UsukiDoll

2. UsukiDoll

ok so first we need the arc length formula which is $s = \theta r$ where s = arc length, $\theta$ = angle , and r is the radius.

3. anonymous

Oh wow they never gave me a formula for this

4. UsukiDoll

so we are given radius = 8 and our angle is 40 degrees, but I need that in radians so I need to convert $40 \times \frac{\pi}{180}$ $\frac{40 \pi}{180}$ $\frac{2\pi}{9}$

5. UsukiDoll

I think we almost got our arc length $s= \frac{2\pi}{9} \times 8$

6. UsukiDoll

just gotta multiply what's 2pi x 8 ?

7. anonymous

Wait a sec I need to get my calculator

8. anonymous

brb

9. UsukiDoll

actually... we can just leave the pi part alone ._. and just calculate 2 x 8 for the numerator.

10. anonymous

Sorry. I'm back now

11. anonymous

2x8=16

12. UsukiDoll

yes so our arc length is $s= \frac{16 \pi}{9}$

13. anonymous

So that makes the answer B

14. anonymous

Thank you so much. Now I'm sure I know how to do this. Especially since now I know what the formula is.

15. UsukiDoll

hmmm... Why weren't you given the formula? It was supposed to be given to you x_X

16. anonymous

I know, but they didn't. At least, it didn't show it on the lesson.

17. anonymous

I'll be right back. It'll be a few minutes

18. anonymous

gtg

19. UsukiDoll

k bye... wow shame on whoever for not giving it. -_-!

20. anonymous

I'm back