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#1 2013-03-07 08:03:42

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!

#2 2013-03-07 08:21:06

Guest

Re: Geometry Formulas

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

#3 2013-03-07 20:10:12

bobbym
Administrator

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Re: Geometry Formulas

Hi;

For a right pyramidal frustum:

Look here for more:

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

Last edited by bobbym (2013-03-07 20:11:26)

In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

#4 2013-03-08 03:08:47

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.

#5 2013-03-08 08:08:02

bobbym
Administrator

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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

In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

#6 2013-03-08 09:48:43

Guest

Re: Geometry Formulas

Sorry I wrote that wrong.

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

#7 2013-03-08 10:48:08

bobbym
Administrator

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Re: Geometry Formulas

Hi;

Okay, you are welcome.

In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

#8 2013-03-09 12:30:13

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?

#9 2013-03-09 12:37:08

bobbym
Administrator

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Re: Geometry Formulas

Hi;

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

In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

#10 2013-03-09 13:37:14

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.

#11 2013-03-09 14:10:53

bobbym
Administrator

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Re: Geometry Formulas

Hi;

The area of a lune can be found right here:

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

In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

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