Question

What is the volume of the cone?


12 cm3

20 cm3

36 cm3

60 cm3

Answer 1

cone

Answer 2

I don't know the formula

Answer 3

The volume of a cone is 1/3 Bh where B is the area of the base.
A cone has a circular base so its area is π r².

That gives V = 1/3 * π r²* h

Answer 4

V = 1/3 * π r²* h

V = 1/3 π 3²* 4

V = ? @Joshuam1 It looks as it you may need to use 3.14 as an approximation for pi. I'll check my answer against yours after you post what you get. Okay?

Answer 5

okay :D

Answer 6

Got an answer yet?

Answer 7

i did 1/3 x b x h

Answer 8

the base is 3 and the height is 4 right?

Answer 9

The base radius is 3. The base area is pi*3*3

Answer 10

You need to do this: 1/3 * π 3²* 4

Answer 11

oh xD
so it's 1/3 x 3.14 x 3 x 3 x 4?

Answer 12

And, that is what?

Answer 13

37.68

Answer 14

That is what I got but it is not one of the options although it is close. Check the problem and the options. Be sure we were not asked to find surface area.

Answer 15

no, that is all
the closest answer is 36

Answer 16

I have another question but it wants to find the surface area of a cone

Answer 17

If all that checks out, go with the 36 is all I know to do.

Answer 18

okay :D

Answer 19

here is the cone for the surface area question. should i just ask a whole new question or just stay in this one?

Answer 20

Surface Area of Cone = π*r*L+ π *r^2
where r is the radius of the base and L is the slant height.

Answer 21

3.14 x 4 x 5 + 3.14 x 4 x 4 ?

Answer 22

Yes, you are correct. Crank it out.

Answer 23

113.04

Answer 24

I used more pi digits and got 113.0973. No big deal.

Answer 25

oh okay

Answer 26

Is that an option or are those options still off as they were on the last problem?

Answer 27

still off
60 cm2

20 cm2

16 cm2

36 cm2

Answer 28

Off is putting it mildly. Aren't those the volume options again? We're doing surface area now.

Answer 29

they gave similar options
not sure why

Answer 30

Surface area includes the base. Lateral area does not include the base. Let's see what the lateral area is.

Answer 31

3.14 x 4 x 5 is the lateral area. What does that equal?

Answer 32

62.8

Answer 33

that's a more realistic answer

Answer 34

You need to talk with the teacher about this. Surface area is 113 ish. Lateral area is 62.8 ish. Both are off the options as was the volume. We should not have to guess what the options are if our work is correct and the problem is correctly stated.

Answer 35

When you talk with the teacher, have your work handy.

Answer 36

yes you are right I will have a talk with her about it and see what is up with that

Answer 37

next question?

Answer 38

5 more I need help with

Answer 39

Put it in a new thread. Once a thread gets longer than 10 to 15 rectangles, this OS program gets herky-jerky on my computer. Something about scripts.

Answer 40

oh alright :)