Question

Find the height of a cone with V = 100 and B = 20.
666.67
15
19.89
24.32

Answer 1

Wanna work together on this?

Answer 2

yea

Answer 3

Awesome. First things first: do you know the volume formula for a cone?

Answer 4

noooo

Answer 5

Okie dokie. Here it is:

1/3 pi r^2 h

Answer 6

Does that make sense? If not, feel free to ask!

Answer 7

yes

Answer 8

Awesome! So we know that volume = pi*r^2*h
We are given: volume and "B". Just wanna double check: in your class, B means Base, or diameter of the circle, right?

Answer 9

yes

Answer 10

Oh, I'm sorry! I just googled it. B is actually the surface base area.

Answer 11

ok

Answer 12

Do you know how we can get the radius given just the base area?

Answer 13

As in, if you know the area of a circle, do you remember how to get the radius of that circle?

Answer 14

yea

Answer 15

Awesome! So tell me what you got the radius as.

Answer 16

Actually, I've got better news!

Answer 17

Area of a circle is pi*r^2
Which is actually in the formula for volume of a cone, right? So what number could we replace the entire "pi*r^2" portion of the formula with?

Answer 18

Hint:
The original formula is
1/3 * pi * r^2 * height

Answer 19

1/3 ???????

Answer 20

Not really. Do you remember what the formula for area of a circle is?

Answer 21

(Hint: I wrote it a few comments up)

Answer 22

pi*r^2"

Answer 23

That's right! And what number did we say is equal to the circle area?

Answer 24

i forgot..