Question

@mathstudent55

Answer 1

You need the formula of the volume of a pyramid.
Do you have a textbook that you are learning math from?

Answer 2

No textbook, is it lwh/3?

Answer 3

I don't know immediately if the volume formula for this will be lwh/3.
I assume your teacher wants you to find this volume using integration?

Answer 4

are you currently learning about finding volumes using integration?

Answer 5

she's not at that level yet

Answer 6

I will get her to that level :)

Answer 7

good luck with that

Answer 8

@mathstudent55
@sourwing - shut up, at least she has confidence!

@miracrown
-It's a pre-assignment; so no I haven't learned it.
I'm not sure about the "integration" part, I just used the equation for a right rectangular pyramid...

Answer 9

@mathstudent55 is correct about the volume being lwh/3.

Answer 10

The volume of a pyramid is 1/3 times the area of the base times the height.

Answer 11

The formula @mathstudent55 correctly reasoned here is fine.

Answer 12

In math terms, the volume of a pyramid is:

\(V = \dfrac{1}{3}LWH\)

Answer 13

@Miracrown Great job as usual!

Answer 14

@Miracrown I'm intrigued though, how do you solve it by integration? =]]

Answer 15

Thank you, @mathstudent55
Using the numbers given to us,
it looks like the volume is 297 cm^3

do you agree @lilia222 ?

Answer 16

Since we are told the pyramid is a "square pyramid", that means the base is a square and the length and width of the base are both 9 cm.

Answer 17

Proving that the formula is indeed lwh/3 takes a bit of effort.

Answer 18

The height is 11 cm.

So we have
L = 9 cm
W = 9 cm
H = 11 cm

Just use those numbers int he formula to find the volume.

Answer 19

Mira- wonderful! :)
Mathstudent- thanks for clarifying that, I thought we were solving for one of those..

Answer 20

@sourwing I'll show you by integration derivation.

Answer 21

@Miracrown please show me. =]]]

Answer 22

Let me setup a coordinate system to help with the details:
I drew the slice in Red

http://screencast.com/t/cvjw1IyuDo

Answer 23

the geometry for this problem can get quite involved.

Answer 24

usually for this type of problem the assumption is made of having a square base.
This will help a great deal with the geometry.

Answer 25

lol ok. I'm just playing with ya. I already know how to use integration. XDD

Answer 26

no no no, let me teach it to you.

Answer 27

I'm not a ball that you can play with, @sourwing

Answer 28

but anyways the KEY to this problem is to express the area of our red square in terms of its height Z.

Answer 29

lol ok. I KNOW how to use integration. So stop lol

Answer 30

lol no wait there is more