Burt (in ) said:

| I can't remember the formula for the life of me.
| If a dish is almost 3 ft across and I want to segment it like an
| orange into 10 segments how do I calculate how wide each will be at
| the rim?
| So I end up with a dish that has 10 sides.
|
| I'm math clueless.

Burt...

Each of the sides will be 36" * sin(360 degrees / 20) or approximately
11-1/8"

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto/solar.html

On 2005-06-27, Morris Dovey wrote:
Burt (in ) said:

| I can't remember the formula for the life of me.
| If a dish is almost 3 ft across and I want to segment it like an
| orange into 10 segments how do I calculate how wide each will be at
| the rim?
| So I end up with a dish that has 10 sides.
|
| I'm math clueless.

Burt...

Each of the sides will be 36" * sin(360 degrees / 20) or approximately
11-1/8"

Too much work and I don't get the same answer anyway. (PI * 36 / 10) =
PI * 3.6 = 11.3097312 etc. etc. etc. Significantly more than 1/8 inch
difference, it's over 11 1/4 inches.

--
I can find no modern furniture that is as well designed and emotionally
satisfying as that made by the Arts and Crafts movement in the early years
of the last century.

"Morris Dovey" wrote in message
...
Burt (in ) said:

| I can't remember the formula for the life of me.
| If a dish is almost 3 ft across and I want to segment it like an
| orange into 10 segments how do I calculate how wide each will be at
| the rim?
| So I end up with a dish that has 10 sides.
|
| I'm math clueless.

Burt...

Each of the sides will be 36" * sin(360 degrees / 20) or approximately
11-1/8"

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto/solar.html



If he were building a 10 segment, flat circle you would be right on
but he said "dish". I suspect he needs the other sides's dimension
as well. More information is necessary to figure it out. How deep
is the dish and does it have an elliptical section or is it part of a
sphere? What is the dish for exactly? There are myriad possibilities
when you say dish so there is no way to give a (complete) correct answer...

Phil Davis
247PalmBeachRE.com

Ed Clarke (in ) said:

| On 2005-06-27, Morris Dovey wrote:
|| Burt (in ) said:
||
||| I can't remember the formula for the life of me.
||| If a dish is almost 3 ft across and I want to segment it like an
||| orange into 10 segments how do I calculate how wide each will be
||| at the rim?
||| So I end up with a dish that has 10 sides.
|||
||| I'm math clueless.
||
|| Burt...
||
|| Each of the sides will be 36" * sin(360 degrees / 20) or
|| approximately 11-1/8"
|
| Too much work and I don't get the same answer anyway. (PI * 36 /
| 10) = PI * 3.6 = 11.3097312 etc. etc. etc. Significantly more than
| 1/8 inch difference, it's over 11 1/4 inches.

Not too much work if your calculator has trig functions. My Windows
calculator came up with 11.124611797498107267682563018581", which
misses 11-1/8 by only 0.0004".

Pi * 36 / 10 would be the arc length of the segment, while 36*sin(18)
is the chord length. The difference is
0.18512175542514839078295316122472", somewhere near 3/16" - so the
extra effort may be worthwhile :-)

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto/solar.html

Phil (in ) said:

| "Morris Dovey" wrote in message
| ...
|| Burt (in ) said:
||
||| I can't remember the formula for the life of me.
||| If a dish is almost 3 ft across and I want to segment it like an
||| orange into 10 segments how do I calculate how wide each will be
||| at the rim?
||| So I end up with a dish that has 10 sides.
|||
||| I'm math clueless.
||
|| Burt...
||
|| Each of the sides will be 36" * sin(360 degrees / 20) or
|| approximately 11-1/8"
||
|| --
|| Morris Dovey
|| DeSoto Solar
|| DeSoto, Iowa USA
|| http://www.iedu.com/DeSoto/solar.html
||
||
|
| If he were building a 10 segment, flat circle you would be right on
| but he said "dish". I suspect he needs the other sides's dimension
| as well. More information is necessary to figure it out. How deep
| is the dish and does it have an elliptical section or is it part of
| a sphere? What is the dish for exactly? There are myriad
| possibilities
| when you say dish so there is no way to give a (complete) correct
| answer...

Phil...

Burt also wrote:
I need to cut ten pieces of steel to form a ten sided form that
will
fit exactly inside a 3 foot circle. I need the distance between the
points as a straight line. so if it section is shaped like a bow I
need the length of the string.

I interpreted this to mean he wanted the straight line distance
between adjacent points on a circle. Since circles are planar objects,
I don't think deformations of the 10 segments enter into /this/
calculation, but I could be wrong ( and frequently am :-)

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto/solar.html

Send me an email and I will send you a CAD drawing. Exact to 8 decimal
places (though the answers you got here are correct). Thought you might want
something on "paper". Will send as PDF.

"Burt" wrote in message
...
Beyond my figuring skills and it has to be exact.
Each of the points has to touch the inside of the 3 foot circle.

"Ed Clarke" wrote in message
...

Too much work and I don't get the same answer anyway. (PI * 36 / 10) =
PI * 3.6 = 11.3097312 etc. etc. etc. Significantly more than 1/8 inch
difference, it's over 11 1/4 inches.


Your answer is to a question that was not asked. Had the OP asked what the
length of the exterior of the segment was you would have been correct.
However the OP asked how wide the segment would be. The widest part would
be the distance between the two closest points of that triangle shaped
segment. That distance between those two points is approximately 11.125".

"Morris Dovey" wrote in message
...
Phil (in ) said:

| "Morris Dovey" wrote in message
| ...
|| Burt (in ) said:
||
||| I can't remember the formula for the life of me.
||| If a dish is almost 3 ft across and I want to segment it like an
||| orange into 10 segments how do I calculate how wide each will be
||| at the rim?
||| So I end up with a dish that has 10 sides.
|||
||| I'm math clueless.
||
|| Burt...
||
|| Each of the sides will be 36" * sin(360 degrees / 20) or
|| approximately 11-1/8"
||
|| --
|| Morris Dovey
|| DeSoto Solar
|| DeSoto, Iowa USA
|| http://www.iedu.com/DeSoto/solar.html
||
||
|
| If he were building a 10 segment, flat circle you would be right on
| but he said "dish". I suspect he needs the other sides's dimension
| as well. More information is necessary to figure it out. How deep
| is the dish and does it have an elliptical section or is it part of
| a sphere? What is the dish for exactly? There are myriad
| possibilities
| when you say dish so there is no way to give a (complete) correct
| answer...

Phil...

Burt also wrote:
I need to cut ten pieces of steel to form a ten sided form that
will
fit exactly inside a 3 foot circle. I need the distance between the
points as a straight line. so if it section is shaped like a bow I
need the length of the string.

I interpreted this to mean he wanted the straight line distance
between adjacent points on a circle. Since circles are planar objects,
I don't think deformations of the 10 segments enter into /this/
calculation, but I could be wrong ( and frequently am :-)

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto/solar.html


Morris,
You are correct and it seems you are not to often incorrect. I
often read your posts and you have some good solutions to the
various problems posted.

While a few others here were using their math skills, I cheated
and used my CAD software to draw the problem and arrived
at the length of (rounded) 11.125".

Phil

On Sun, 26 Jun 2005 22:10:09 -0400, "Phil" wrote:


"Morris Dovey" wrote in message
...
Burt (in ) said:

| I can't remember the formula for the life of me.
| If a dish is almost 3 ft across and I want to segment it like an
| orange into 10 segments how do I calculate how wide each will be at
| the rim?
| So I end up with a dish that has 10 sides.

If he were building a 10 segment, flat circle you would be right on
but he said "dish". I suspect he needs the other sides's dimension
as well. More information is necessary to figure it out. How deep
is the dish and does it have an elliptical section or is it part of a
sphere? What is the dish for exactly? There are myriad possibilities
when you say dish so there is no way to give a (complete) correct answer...

Nah, you're making it too complex. The difference in the two answers
given is that one is the length from point to point on the circle
(Morris's answer, approx 11.125"), useful if the OP is making ten
segments with straight edges, and the other is the length of the curve
(approx 11.3"), useful if the segments need tobe curved to fit the rim
exactly. We don't need to know how deep the dish is to figure it out.