Side length of a pyramid

[silverdragon316]

This is my problem:

What is the side length of a pyramid 12ft high with a volume of 144ft^3?

How should I go about setting this up?

What formula should I use?

 

[stapel]

What formula should I use?

What formula(s) did they give you?

Thank you.

Eliz.

 

[silverdragon316]

What formula(s) did they give you?

none. That is all I was given.

 

[stapel]

What formula(s) did they give you?

none. That is all I was given.

If they gave you no formula, then you must have been expected to know this already. So go online, do a search for "area volume pyramid" (without the quote-marks, of course), find some formulas, and apply.

And, when you're done, memorize!!

Eliz.

 

[silverdragon316]

If they gave you no formula, then you must have been expected to know this already. So go online, do a search for "area volume pyramid" (without the quote-marks, of course), find some formulas, and apply.

And, when you're done, memorize!!

ok, I will thanks.

 

[TchrWill]

What is the side length of a pyramid 12ft high with a volume of 144ft^3?

How should I go about setting this up? What formula should I use?

The volume of a pyramid is given by V = bh/s where b = the length of the base sides and h = the height of the pyramid.

Therefore, 144 = b(12)/3 making b = 18 ft.

Viewing half the pyramid, the slant height (the altitude of the slant face of the pyramid) derives from sh = sqrt(12^2 + 18^2) = 21.633 ft.

Looking at the face of the pyramid, the length of the sides (from the apex to the base corners), s, derive from s = sqrt(21.633^2 + 18^2) = 28.14 ft.