## Skittles10412 one year ago 4. What is the value of x, if the volume of the cone is 12m3? (1 point) 4 m 5 m 6 m 10 m

1. Skittles10412

2. Skittles10412

for the 12m^3 it should be 12pim^3

3. electrokid

volume of cone is: $V={1\over3}\pi r^2 h$ we have V=12m^3 r = (6/2)=3m find h = ?

4. Skittles10412

would the answer be 4? for the height???

5. electrokid

How? none of the options are right

6. Skittles10412

because how i got it was right it was 4 and i did that by doing 1/3*3^2 and got 3 and the only one that would get me to 12 was 4 because 3*4= 12

7. Chelsea04

yea, it'd be 4 for the height

8. electrokid

what happened to the $$\pi$$

9. electrokid

the question must have volume as $$12\pi\,{\rm m^3}$$

11. Chelsea04

you could use pythagoras' theorem to work out the height btw...cause it is a right angled triangle.

12. Skittles10412

I didnt know that I could use that. ^_^

13. Chelsea04

14. Skittles10412

oh yeah now i remember lol this home schooling thing has kinda gottin my mind going a lil slow lol

15. Chelsea04

you could also substitute values into the formula and solve for h, which is the preferred method

16. electrokid

are you still sure the question does not have a "pi" in there?

17. Chelsea04

didn't @Skittles10412 write that 'for the 12 m^3 it should be 12pi m^3' at the top of the page?

18. Skittles10412

yeah im positive i finished the questions and i got 4m

19. Skittles10412

yeah i had to retype it to make sure that people who were going to help me knew that it was 12pi m^3 not 12m^3

20. Chelsea04

ok, sure thing!

21. Skittles10412

yup and than you to every one who helped me :)

22. Whiterabbit541

volume of cone = (1/3)(pi) x r^2 x h (pi) = 3.14159265359 6/2 = 3 12(pi) = (1/3)(pi) x 3^2 x h 12(pi) x 3 = (1/3 x 3/1) (pi) x 3^2 x h 36(pi) = (pi) x 3^2 x h 36(pi) = (pi) x 9 x h 36(pi)/(pi) = (pi)/(pi) x 9 x h 36 = 9 x h 36/9 = 9/9 x h 4 = h Answer = a) 4 m