## anonymous one year ago A giant pie is created in an attempt to break a world record for baking. The pie is shown below: A circle is shown with a central angle marked 42 degrees and the diameter marked 30 feet. What is the area of the slice of pie that was cut, rounded to the nearest hundredth? 78.13 ft2 82.43 ft2 86.31 ft2 91.98 ft2

1. anonymous

The ratio of the slice's area to the circle's area is the same as the ratio of the angle to 360° $\frac{ 42 }{ 360 }=\frac{ x }{\pi r^2 }$

2. welshfella

do you need any more help? can you work out the value of the radius ( r )?

3. anonymous

How do I find the radius?

4. anonymous

divide the diameter by 2

5. welshfella

radius = half of the diameter

6. anonymous

so id d=30 then the radius is 15?

7. anonymous

yes

8. anonymous

ok so I would do x/pi*15^2 ?

9. anonymous

I'd get a number for π*15² then cross multiply to find x. x is the area you're looking for

10. anonymous

ok so 42/360=x/706.5 then multiply 42 and 706.5 29673 so its 360x/29673 ?

11. anonymous

yes

12. anonymous

360x = actually

13. anonymous

wait what?

14. anonymous

360x=29673

15. anonymous

oh ok. so its 29673 divided by the 360

16. anonymous

yes

17. anonymous

so the answer would be 82.425 ?

18. anonymous

right

19. anonymous

THANK YOU SO MUCH!!!

20. anonymous

you're welcome

21. anonymous

I'm new to the site how to I give you like an awards or something?

22. anonymous

just hit the "best answer button" on a response from whomever you want to give a medal to

23. anonymous

Ok. Can you help me on one just like this one? I think I got it but I want to be sure

24. anonymous

A Ferris wheel car moves from point C to point D on the circle shown below: Circle A is shown with a central angle marked 38 degrees and the diameter marked 20 feet. What is the arc length the car traveled, to the nearest hundredth? 2.18 feet 4.31 feet 5.84 feet 6.63 feet

25. anonymous

38/360=x/pi*10^2 38/360=x/314 360x=11932 x=33.144

26. anonymous

Wait, I don't think I read the question right.....

27. anonymous

you did it right, you just used the wrong formula. Area is πr². Circumference is 2πr. Arc length is part of the circumference. 38/360=x/(2πr) 38/360=x/(2π*10) 38/360=x/62.8 360x= 2386.4 x=6.62

28. anonymous

Thank you!