Math Is Fun Forum

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Guest

Geometry Formulas

I was just curious, what is the formula for the surface area and volume,

and

respectively, for a pyramidal frustum and a conical frustum? I would prefer you to put it in LaTeX so I can easily understand it. Thanks!
Note: later I may ask for other formulas, so don't put away your brain when you're done!

∞

Guest

Re: Geometry Formulas

Oops, I almost forgot; I would also like a picture showing where the demensions are. Thanks...again!

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Geometry Formulas

Hi;

For a right pyramidal frustum:

Look here for more:

http://mathworld.wolfram.com/PyramidalFrustum.html

Last edited by bobbym (2013-03-06 21:11:26)

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In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

∞

Guest

Re: Geometry Formulas

Thanks!
I do want to ask though, is a right frustum just a straight, generic one? Or is it one that is tilted?
Also, I checked out the link, and it seems that the full surface area (as in, the whole surface of it including bases) is:

, where

is multiplication.
Am I right? I am kind of confused. The volume formula though, is easy for me to understand.

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Geometry Formulas

Hi;

It is much better to write it like this:

check out this url:

http://www.ditutor.com/solid_gometry/fr … ramid.html

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In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

∞

Guest

Re: Geometry Formulas

Sorry I wrote that wrong.

Thanks, again; I think I now understand it. (:

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Geometry Formulas

Hi;

Okay, you are welcome.

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

∞

Guest

Re: Geometry Formulas

Next geometry question I've been wondering:
What is the perimeter

of annulus?
I was thinking it was

where

is the larger radius, but what about the inner part?
Is that included in the formla, or is it just the 'strict' outside?

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Geometry Formulas

Hi;

The perimeter of an annulus is the sum of the perimeter of the two circles, interior and exterior.

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In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

∞

Guest

Re: Geometry Formulas

6 more (these might be tougher than before):

1. A & P of a Lune of Hippocrates.

2. V & S of spherical cap.

3. V & S of a spherical sector.

4. V & S of a spherical segment.

5. V & S of a spherical shell.

6. V & S of a spherical wedge.

Where V = volume, S = surface area, A = area, P = perimeter.

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Geometry Formulas

Hi;

The area of a lune can be found right here:

http://mathworld.wolfram.com/Lune.html

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In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.