Question

URGENT: VOLUME OF A PYRAMID!!!!

Answer 1

http://lmgtfy.com/?q=volume+of+a+pyramid

Answer 2

its a complicated problem

Answer 3

@haley321 Please post the problem.

Answer 4

A square pyramid has a lateral area of 2,684 cm squared. If the base has a side length of 22cm, what is the volume o the pyramid? (Hint:Find the slant height first)

Answer 5

Let me find a diagram.

Answer 6

ok

Answer 7

If the lateral area is 2684, then each of the four congruent triangles forming the lateral area has individual area 2684/4 = 671. Do you agree?

Answer 8

yes i got that

Answer 9

The slant height l (l as in "ell") of the pyramid is the altitude of an individual triangular face.

Answer 10

So, solve this equation for L to get the slant height of the regular pyramid

671 = (1/2)*22*L

Answer 11

We need the slant height to get the height of the pyramid for its volume.

Answer 12

@haley321 L = ?

Answer 13

i dont know

Answer 14

(1/2)*22*L = 671

11L = 671

What number times 11 equals 671?

Answer 15

61

Answer 16

how did you get that eqaution

Answer 17

The area of a triangle is one-half its base times the altitude drawn to that base.

Answer 18

Look at this diagram above:

regularsquarebasepyramid1.jpg

Answer 19

ok i understand, how do i find the volume

Answer 20

Now, to get the altitude of the pyramid.

h^2 + 11^2 = 61^2 --> Pythagorean Theorem

Solve that for h.

Answer 21

Super cool. The sides are a Pythagorean Triple.

(11, 60, 61)

Answer 22

h=60

Answer 23

61

Answer 24

The last equation to solve:
Volume of Pyramid = (1/3) * B * h where B is the area of the base of the pyramid and h is the altitude of the pyramid.

Answer 25

V = (1/3) * 22 * 22 * 60 --> Note: 22*22 is the area of the square base.
V = ?

Answer 26

is this right ? v=14,762 cm cubed

Answer 27

i mean 9,841.3

Answer 28

I did not get that answer. Would you post your calculations? Thanks.

Answer 29

I did not get that. Maybe I am the one who should post the calculation.

Answer 30

(1/3) * 22 * 22 * 60 =
(1/3) * 60 * 22 * 22 =
20 * 22 * 22 = ?

Answer 31

@haley321 20 * 22 * 22 = ?

Answer 32

22*22=484 which is the base, multiply by 61 and divide by two.

Answer 33

And the final answer is ?

Answer 34

The volume of the pyramid is ?

Answer 35

9,841.3

Answer 36

@hayley321 Why are you multiplying by 61?

61 is the slant height, not the height of the pyramid.

Look at the diagram.

Answer 37

Volume = (1/3) * 22 * 22 * 60

NOT (1/3) * 22 * 22 * 61 --> NO

Answer 38

ok thanks

Answer 39

And, the answer is ?

Answer 40

And, the answer is ?