Question

Find the length of the base of a square pyramid if the volume is 1,024 cubic inches and has a height of 12 inches. Use 3.14 for pi and round your answer to the nearest hundredth.
Select one:
a. 4 inches
b. 8 inches
c. 16 inches
d. 24 inches

Answer 1

See the formula for volume of (general) square pyramid - http://en.wikipedia.org/wiki/Square_pyramid#Other_square_pyramids

Can you answer the question now ??

Answer 2

What equation do I use? @LastDayWork

Answer 3

For square pyramids in general, with base length l and height h, volume is:
\[V=\frac{ 1 }{ 3 } l^2 h\]

Answer 4

So then would it be set up like: 1024=1/3L(12)

Answer 5

@LastDayWork

Answer 6

Yep..the equation is correct.
We can now solve for l :)

Answer 7

Okay...So first I would multiply 1/3 and 12, which comes out to 4. Then the equation is 1024=4L. Now what?

Answer 8

@LastDayWork

Answer 9

A correction; it's L^2
So
\[1024 = 4L^2\]

We can add or subtract a number on both sides of equal to.
We can multiply or divide a (non-zero) number on both sides of equal to

So,
\[1024 = 4L^2\]
\[\frac{ 1024 }{ 4 }=\frac{ 4L^2 }{ 4 }\]
Can you simplify it ??

Answer 10

It would be 16 :) Because 1024/4 is 256, and the square root of that is 16 :)

Answer 11

That's correct :)