RE: [Flashcoders] Area of a triangle using perimiter values only
I'd stick to using Heron's rule -- there is no reason why it shouldn't work given correct inputs, and it is less expensive computationally. Without doing the maths, I suspect that eliminating the sin/cos from the two formulas will probably produce Heron's formula in any case. Danny ___ Flashcoders@chattyfig.figleaf.com To change your subscription options or search the archive: http://chattyfig.figleaf.com/mailman/listinfo/flashcoders Brought to you by Fig Leaf Software Premier Authorized Adobe Consulting and Training http://www.figleaf.com http://training.figleaf.com
RE: [Flashcoders] Area of a triangle using perimiter values only
I'd stick to using Heron's rule -- there is no reason why it shouldn't work given correct inputs, and it is less expensive computationally. Yeah, but then by switching, I'd be insulting the other Mathematician dude who invented divide by 4 equation, just for the sake of pleasing Heron. I dunno. I think I'll have to sleep on it. Jason Merrill Bank of America Learning Organizational Effectiveness ___ Flashcoders@chattyfig.figleaf.com To change your subscription options or search the archive: http://chattyfig.figleaf.com/mailman/listinfo/flashcoders Brought to you by Fig Leaf Software Premier Authorized Adobe Consulting and Training http://www.figleaf.com http://training.figleaf.com
[Flashcoders] Area of a triangle using perimiter values only
I'm trying to figure the area of a triangle in Actionscript using the
perimeter values only, not the traditional simple formula:
area = (height/2)*base
because figuring the height is tricky given the triangle will be drawn
in odd ways (i.e. a not horizontally alinged base), so I am exploring
other triangle area forumulas that only take in the perimiter values
(a,b,c), like Heron's formula or this one, which I like:
given a,b,c are the length of the sides of the triangle, then the
formula is:
squareRoot of: (a+b+c)(b+c-a)(c+a-b)(a+b-c)
___
4
So in trying to translate that to actionscript, I wrote:
public static function areaOfTriangle(a:Number, b:Number,
c:Number):Number{
return (Math.sqrt((a+b+c)*(b+c-a)*(c+a-b)*(a+b-c)))/4;
}
But the problem is (a+b+c)*(b+c-a)*(c+a-b)*(a+b-c) results in a negative
number, and this the square root cannot be taken. Or perhaps I am
interpreting the forumula incorrectly:
http://mathworld.wolfram.com/TriangleArea.html
What am I doing wrong here? Thanks.
Jason Merrill
Bank of America
Learning Organizational Effectiveness
___
Flashcoders@chattyfig.figleaf.com
To change your subscription options or search the archive:
http://chattyfig.figleaf.com/mailman/listinfo/flashcoders
Brought to you by Fig Leaf Software
Premier Authorized Adobe Consulting and Training
http://www.figleaf.com
http://training.figleaf.com
Re: [Flashcoders] Area of a triangle using perimiter values only
To dodge your question, couldn't you just use the simple distance
forumula to determine the base even when it's not horizontal? I dont'
know much about your application or if you'll have the points where
the triangle's points lie, but that's just an idea.
Oh, but I just thought of something from my old rusty brain. I looked
at the formula on the mathworld page; would that not indicate a
distributive method of multiplication? Again, rusty, but a thought.
Let us know what you figure out!!
Cheers
On 12/14/06, Merrill, Jason [EMAIL PROTECTED] wrote:
I'm trying to figure the area of a triangle in Actionscript using the
perimeter values only, not the traditional simple formula:
area = (height/2)*base
because figuring the height is tricky given the triangle will be drawn
in odd ways (i.e. a not horizontally alinged base), so I am exploring
other triangle area forumulas that only take in the perimiter values
(a,b,c), like Heron's formula or this one, which I like:
given a,b,c are the length of the sides of the triangle, then the
formula is:
squareRoot of: (a+b+c)(b+c-a)(c+a-b)(a+b-c)
___
4
So in trying to translate that to actionscript, I wrote:
public static function areaOfTriangle(a:Number, b:Number,
c:Number):Number{
return (Math.sqrt((a+b+c)*(b+c-a)*(c+a-b)*(a+b-c)))/4;
}
But the problem is (a+b+c)*(b+c-a)*(c+a-b)*(a+b-c) results in a negative
number, and this the square root cannot be taken. Or perhaps I am
interpreting the forumula incorrectly:
http://mathworld.wolfram.com/TriangleArea.html
What am I doing wrong here? Thanks.
Jason Merrill
Bank of America
Learning Organizational Effectiveness
___
Flashcoders@chattyfig.figleaf.com
To change your subscription options or search the archive:
http://chattyfig.figleaf.com/mailman/listinfo/flashcoders
Brought to you by Fig Leaf Software
Premier Authorized Adobe Consulting and Training
http://www.figleaf.com
http://training.figleaf.com
--
Jordan Snyder
jordansnyder.com
Applications Developer
Image Action LLC
http://www.imageaction.com
___
Flashcoders@chattyfig.figleaf.com
To change your subscription options or search the archive:
http://chattyfig.figleaf.com/mailman/listinfo/flashcoders
Brought to you by Fig Leaf Software
Premier Authorized Adobe Consulting and Training
http://www.figleaf.com
http://training.figleaf.com
Re: Re: [Flashcoders] Area of a triangle using perimiter values only
I recind half of what I said after actually thinking about it, but
maybe it's a different perspective ;)
On 12/14/06, Jordan Snyder [EMAIL PROTECTED] wrote:
To dodge your question, couldn't you just use the simple distance
forumula to determine the base even when it's not horizontal? I dont'
know much about your application or if you'll have the points where
the triangle's points lie, but that's just an idea.
Oh, but I just thought of something from my old rusty brain. I looked
at the formula on the mathworld page; would that not indicate a
distributive method of multiplication? Again, rusty, but a thought.
Let us know what you figure out!!
Cheers
On 12/14/06, Merrill, Jason [EMAIL PROTECTED] wrote:
I'm trying to figure the area of a triangle in Actionscript using the
perimeter values only, not the traditional simple formula:
area = (height/2)*base
because figuring the height is tricky given the triangle will be drawn
in odd ways (i.e. a not horizontally alinged base), so I am exploring
other triangle area forumulas that only take in the perimiter values
(a,b,c), like Heron's formula or this one, which I like:
given a,b,c are the length of the sides of the triangle, then the
formula is:
squareRoot of: (a+b+c)(b+c-a)(c+a-b)(a+b-c)
___
4
So in trying to translate that to actionscript, I wrote:
public static function areaOfTriangle(a:Number, b:Number,
c:Number):Number{
return (Math.sqrt((a+b+c)*(b+c-a)*(c+a-b)*(a+b-c)))/4;
}
But the problem is (a+b+c)*(b+c-a)*(c+a-b)*(a+b-c) results in a negative
number, and this the square root cannot be taken. Or perhaps I am
interpreting the forumula incorrectly:
http://mathworld.wolfram.com/TriangleArea.html
What am I doing wrong here? Thanks.
Jason Merrill
Bank of America
Learning Organizational Effectiveness
___
Flashcoders@chattyfig.figleaf.com
To change your subscription options or search the archive:
http://chattyfig.figleaf.com/mailman/listinfo/flashcoders
Brought to you by Fig Leaf Software
Premier Authorized Adobe Consulting and Training
http://www.figleaf.com
http://training.figleaf.com
--
Jordan Snyder
jordansnyder.com
Applications Developer
Image Action LLC
http://www.imageaction.com
--
Jordan Snyder
Applications Developer
Image Action LLC
http://www.imageaction.com
___
Flashcoders@chattyfig.figleaf.com
To change your subscription options or search the archive:
http://chattyfig.figleaf.com/mailman/listinfo/flashcoders
Brought to you by Fig Leaf Software
Premier Authorized Adobe Consulting and Training
http://www.figleaf.com
http://training.figleaf.com
RE: [Flashcoders] Area of a triangle using perimiter values only
I'm trying to figure the area of a triangle in Actionscript using the perimeter values only, not the traditional simple formula: area = (height/2)*base Try: area = 1/2 * a * b * sin(C), where C is the angle between the two sides a and b. You can calculate C using the cosine rule: c^2 = a^2 + b^2 - 2ab * cos(C). A bit of manipulation will give you sin(C) in terms of cos(C) so you can avoid using any trig (sorry I have to rush so I don't have time to do it right now) HTH Danny ___ Flashcoders@chattyfig.figleaf.com To change your subscription options or search the archive: http://chattyfig.figleaf.com/mailman/listinfo/flashcoders Brought to you by Fig Leaf Software Premier Authorized Adobe Consulting and Training http://www.figleaf.com http://training.figleaf.com
RE: [Flashcoders] Area of a triangle using perimiter values only
To dodge your question, couldn't you just use the simple
distance forumula to determine the base even when it's not
horizontal?
yes, I could, but again, that's not what I'm after - I want to get the
area based on the length of the sides. Thanks though.
would that not
indicate a distributive method of multiplication?
My brain is even rustier - can you explain?
I had thought
(a+1)(b+1)(c+1) meant (a+1)*(b+1)*(c+1) but then maybe I'm off?
Jason Merrill
Bank of America
Learning Organizational Effectiveness
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf
Of Jordan Snyder
Sent: Thursday, December 14, 2006 11:27 AM
To: Flashcoders mailing list
Subject: Re: [Flashcoders] Area of a triangle using perimiter
values only
To dodge your question, couldn't you just use the simple
distance forumula to determine the base even when it's not
horizontal? I dont'
know much about your application or if you'll have the points
where the triangle's points lie, but that's just an idea.
Oh, but I just thought of something from my old rusty brain.
I looked at the formula on the mathworld page; would that not
indicate a distributive method of multiplication? Again,
rusty, but a thought.
Let us know what you figure out!!
Cheers
On 12/14/06, Merrill, Jason [EMAIL PROTECTED] wrote:
I'm trying to figure the area of a triangle in Actionscript
using the
perimeter values only, not the traditional simple formula:
area = (height/2)*base
because figuring the height is tricky given the triangle
will be drawn
in odd ways (i.e. a not horizontally alinged base), so I am
exploring
other triangle area forumulas that only take in the
perimiter values
(a,b,c), like Heron's formula or this one, which I like:
given a,b,c are the length of the sides of the triangle, then the
formula is:
squareRoot of: (a+b+c)(b+c-a)(c+a-b)(a+b-c)
___
4
So in trying to translate that to actionscript, I wrote:
public static function areaOfTriangle(a:Number, b:Number,
c:Number):Number{
return
(Math.sqrt((a+b+c)*(b+c-a)*(c+a-b)*(a+b-c)))/4;
}
But the problem is (a+b+c)*(b+c-a)*(c+a-b)*(a+b-c) results in a
negative number, and this the square root cannot be taken.
Or perhaps
I am interpreting the forumula incorrectly:
http://mathworld.wolfram.com/TriangleArea.html
What am I doing wrong here? Thanks.
Jason Merrill
Bank of America
Learning Organizational Effectiveness
___
Flashcoders@chattyfig.figleaf.com
To change your subscription options or search the archive:
http://chattyfig.figleaf.com/mailman/listinfo/flashcoders
Brought to you by Fig Leaf Software
Premier Authorized Adobe Consulting and Training
http://www.figleaf.com http://training.figleaf.com
--
Jordan Snyder
jordansnyder.com
Applications Developer
Image Action LLC
http://www.imageaction.com
___
Flashcoders@chattyfig.figleaf.com
To change your subscription options or search the archive:
http://chattyfig.figleaf.com/mailman/listinfo/flashcoders
Brought to you by Fig Leaf Software
Premier Authorized Adobe Consulting and Training
http://www.figleaf.com
http://training.figleaf.com
___
Flashcoders@chattyfig.figleaf.com
To change your subscription options or search the archive:
http://chattyfig.figleaf.com/mailman/listinfo/flashcoders
Brought to you by Fig Leaf Software
Premier Authorized Adobe Consulting and Training
http://www.figleaf.com
http://training.figleaf.com
Re: Re: Re: [Flashcoders] Area of a triangle using perimiter values only
ALL RIGHT
I'm a silly billy. I used your code and it works just fine. Maybe
the problem isn't in this function.
I'm using Flash 8/AS2.
Cheers
On 12/14/06, Jordan Snyder [EMAIL PROTECTED] wrote:
I recind half of what I said after actually thinking about it, but
maybe it's a different perspective ;)
On 12/14/06, Jordan Snyder [EMAIL PROTECTED] wrote:
To dodge your question, couldn't you just use the simple distance
forumula to determine the base even when it's not horizontal? I dont'
know much about your application or if you'll have the points where
the triangle's points lie, but that's just an idea.
Oh, but I just thought of something from my old rusty brain. I looked
at the formula on the mathworld page; would that not indicate a
distributive method of multiplication? Again, rusty, but a thought.
Let us know what you figure out!!
Cheers
On 12/14/06, Merrill, Jason [EMAIL PROTECTED] wrote:
I'm trying to figure the area of a triangle in Actionscript using the
perimeter values only, not the traditional simple formula:
area = (height/2)*base
because figuring the height is tricky given the triangle will be drawn
in odd ways (i.e. a not horizontally alinged base), so I am exploring
other triangle area forumulas that only take in the perimiter values
(a,b,c), like Heron's formula or this one, which I like:
given a,b,c are the length of the sides of the triangle, then the
formula is:
squareRoot of: (a+b+c)(b+c-a)(c+a-b)(a+b-c)
___
4
So in trying to translate that to actionscript, I wrote:
public static function areaOfTriangle(a:Number, b:Number,
c:Number):Number{
return (Math.sqrt((a+b+c)*(b+c-a)*(c+a-b)*(a+b-c)))/4;
}
But the problem is (a+b+c)*(b+c-a)*(c+a-b)*(a+b-c) results in a negative
number, and this the square root cannot be taken. Or perhaps I am
interpreting the forumula incorrectly:
http://mathworld.wolfram.com/TriangleArea.html
What am I doing wrong here? Thanks.
Jason Merrill
Bank of America
Learning Organizational Effectiveness
___
Flashcoders@chattyfig.figleaf.com
To change your subscription options or search the archive:
http://chattyfig.figleaf.com/mailman/listinfo/flashcoders
Brought to you by Fig Leaf Software
Premier Authorized Adobe Consulting and Training
http://www.figleaf.com
http://training.figleaf.com
--
Jordan Snyder
jordansnyder.com
Applications Developer
Image Action LLC
http://www.imageaction.com
--
Jordan Snyder
Applications Developer
Image Action LLC
http://www.imageaction.com
--
Jordan Snyder
Applications Developer
Image Action LLC
http://www.imageaction.com
___
Flashcoders@chattyfig.figleaf.com
To change your subscription options or search the archive:
http://chattyfig.figleaf.com/mailman/listinfo/flashcoders
Brought to you by Fig Leaf Software
Premier Authorized Adobe Consulting and Training
http://www.figleaf.com
http://training.figleaf.com
RE: Re: [Flashcoders] Area of a triangle using perimiter values only
Without looking up the source of that formula (i.e., just based on what
you wrote), I determine this: that in order for the result of
multiplication to be negative, one of the terms containing subtraction
must be negative. In order for that to occur, one side of your triangle
is longer than the sum of the other two. That is impossible. Check
your parameters.
P.
-Original Message-
From: [EMAIL PROTECTED] [mailto:flashcoders-
[EMAIL PROTECTED] On Behalf Of Jordan Snyder
Sent: Thursday, December 14, 2006 11:36 AM
To: Flashcoders mailing list
Subject: Re: Re: [Flashcoders] Area of a triangle using perimiter
values
only
I recind half of what I said after actually thinking about it, but
maybe it's a different perspective ;)
On 12/14/06, Jordan Snyder [EMAIL PROTECTED] wrote:
To dodge your question, couldn't you just use the simple distance
forumula to determine the base even when it's not horizontal? I
dont'
know much about your application or if you'll have the points where
the triangle's points lie, but that's just an idea.
Oh, but I just thought of something from my old rusty brain. I
looked
at the formula on the mathworld page; would that not indicate a
distributive method of multiplication? Again, rusty, but a
thought.
Let us know what you figure out!!
Cheers
On 12/14/06, Merrill, Jason [EMAIL PROTECTED]
wrote:
I'm trying to figure the area of a triangle in Actionscript using
the
perimeter values only, not the traditional simple formula:
area = (height/2)*base
because figuring the height is tricky given the triangle will be
drawn
in odd ways (i.e. a not horizontally alinged base), so I am
exploring
other triangle area forumulas that only take in the perimiter
values
(a,b,c), like Heron's formula or this one, which I like:
given a,b,c are the length of the sides of the triangle, then the
formula is:
squareRoot of: (a+b+c)(b+c-a)(c+a-b)(a+b-c)
___
4
So in trying to translate that to actionscript, I wrote:
public static function areaOfTriangle(a:Number, b:Number,
c:Number):Number{
return (Math.sqrt((a+b+c)*(b+c-a)*(c+a-b)*(a+b-
c)))/4;
}
But the problem is (a+b+c)*(b+c-a)*(c+a-b)*(a+b-c) results in a
negative
number, and this the square root cannot be taken. Or perhaps I
am
interpreting the forumula incorrectly:
http://mathworld.wolfram.com/TriangleArea.html
What am I doing wrong here? Thanks.
Jason Merrill
Bank of America
Learning Organizational Effectiveness
___
Flashcoders@chattyfig.figleaf.com
To change your subscription options or search the archive:
http://chattyfig.figleaf.com/mailman/listinfo/flashcoders
Brought to you by Fig Leaf Software
Premier Authorized Adobe Consulting and Training
http://www.figleaf.com
http://training.figleaf.com
--
Jordan Snyder
jordansnyder.com
Applications Developer
Image Action LLC
http://www.imageaction.com
--
Jordan Snyder
Applications Developer
Image Action LLC
http://www.imageaction.com
___
Flashcoders@chattyfig.figleaf.com
To change your subscription options or search the archive:
http://chattyfig.figleaf.com/mailman/listinfo/flashcoders
Brought to you by Fig Leaf Software
Premier Authorized Adobe Consulting and Training
http://www.figleaf.com
http://training.figleaf.com
___
Flashcoders@chattyfig.figleaf.com
To change your subscription options or search the archive:
http://chattyfig.figleaf.com/mailman/listinfo/flashcoders
Brought to you by Fig Leaf Software
Premier Authorized Adobe Consulting and Training
http://www.figleaf.com
http://training.figleaf.com
Re: [Flashcoders] Area of a triangle using perimiter values only
Hi Jason
If the number is coming out negative the most likely reason is that
the numbers you are supplying do not make a triangle. (e.g. two sides
are length 1 each and the third is 2 or more). I've tested your code
and it does produce positive numbers for all valid triangles I've
tried.
Jake
On 14/12/06, Merrill, Jason [EMAIL PROTECTED] wrote:
I'm trying to figure the area of a triangle in Actionscript using the
perimeter values only, not the traditional simple formula:
area = (height/2)*base
because figuring the height is tricky given the triangle will be drawn
in odd ways (i.e. a not horizontally alinged base), so I am exploring
other triangle area forumulas that only take in the perimiter values
(a,b,c), like Heron's formula or this one, which I like:
given a,b,c are the length of the sides of the triangle, then the
formula is:
squareRoot of: (a+b+c)(b+c-a)(c+a-b)(a+b-c)
___
4
So in trying to translate that to actionscript, I wrote:
public static function areaOfTriangle(a:Number, b:Number,
c:Number):Number{
return (Math.sqrt((a+b+c)*(b+c-a)*(c+a-b)*(a+b-c)))/4;
}
But the problem is (a+b+c)*(b+c-a)*(c+a-b)*(a+b-c) results in a negative
number, and this the square root cannot be taken. Or perhaps I am
interpreting the forumula incorrectly:
http://mathworld.wolfram.com/TriangleArea.html
What am I doing wrong here? Thanks.
Jason Merrill
Bank of America
Learning Organizational Effectiveness
___
Flashcoders@chattyfig.figleaf.com
To change your subscription options or search the archive:
http://chattyfig.figleaf.com/mailman/listinfo/flashcoders
Brought to you by Fig Leaf Software
Premier Authorized Adobe Consulting and Training
http://www.figleaf.com
http://training.figleaf.com
___
Flashcoders@chattyfig.figleaf.com
To change your subscription options or search the archive:
http://chattyfig.figleaf.com/mailman/listinfo/flashcoders
Brought to you by Fig Leaf Software
Premier Authorized Adobe Consulting and Training
http://www.figleaf.com
http://training.figleaf.com
Re: [Flashcoders] Area of a triangle using perimiter values only
Negative result of ((a+b+c)*(b+c-a)*(c+a-b)*(a+b-c)) is not possible if a,b,
and c are lengths of a triangle's sides. The first term will always be
obviously positive, and so will the other three terms -- they are simply
the sum of the lengths of two sides less the third side, and you can't have
a triangle where that isn't true. It's most likely that your input numbers
to the formula are incorrect. Trace that to find your problem.
On 12/14/06, Merrill, Jason [EMAIL PROTECTED] wrote:
I'm trying to figure the area of a triangle in Actionscript using the
perimeter values only, not the traditional simple formula:
area = (height/2)*base
because figuring the height is tricky given the triangle will be drawn
in odd ways (i.e. a not horizontally alinged base), so I am exploring
other triangle area forumulas that only take in the perimiter values
(a,b,c), like Heron's formula or this one, which I like:
given a,b,c are the length of the sides of the triangle, then the
formula is:
squareRoot of: (a+b+c)(b+c-a)(c+a-b)(a+b-c)
___
4
So in trying to translate that to actionscript, I wrote:
public static function areaOfTriangle(a:Number, b:Number,
c:Number):Number{
return (Math.sqrt((a+b+c)*(b+c-a)*(c+a-b)*(a+b-c)))/4;
}
But the problem is (a+b+c)*(b+c-a)*(c+a-b)*(a+b-c) results in a negative
number, and this the square root cannot be taken. Or perhaps I am
interpreting the forumula incorrectly:
http://mathworld.wolfram.com/TriangleArea.html
What am I doing wrong here? Thanks.
Jason Merrill
Bank of America
Learning Organizational Effectiveness
___
Flashcoders@chattyfig.figleaf.com
To change your subscription options or search the archive:
http://chattyfig.figleaf.com/mailman/listinfo/flashcoders
Brought to you by Fig Leaf Software
Premier Authorized Adobe Consulting and Training
http://www.figleaf.com
http://training.figleaf.com
___
Flashcoders@chattyfig.figleaf.com
To change your subscription options or search the archive:
http://chattyfig.figleaf.com/mailman/listinfo/flashcoders
Brought to you by Fig Leaf Software
Premier Authorized Adobe Consulting and Training
http://www.figleaf.com
http://training.figleaf.com
Re: [Flashcoders] Area of a triangle using perimiter values only
I'd stick to using Heron's rule -- there is no reason why it shouldn't work given correct inputs, and it is less expensive computationally. On 12/14/06, Danny Kodicek [EMAIL PROTECTED] wrote: I'm trying to figure the area of a triangle in Actionscript using the perimeter values only, not the traditional simple formula: area = (height/2)*base Try: area = 1/2 * a * b * sin(C), where C is the angle between the two sides a and b. You can calculate C using the cosine rule: c^2 = a^2 + b^2 - 2ab * cos(C). A bit of manipulation will give you sin(C) in terms of cos(C) so you can avoid using any trig (sorry I have to rush so I don't have time to do it right now) HTH Danny ___ Flashcoders@chattyfig.figleaf.com To change your subscription options or search the archive: http://chattyfig.figleaf.com/mailman/listinfo/flashcoders Brought to you by Fig Leaf Software Premier Authorized Adobe Consulting and Training http://www.figleaf.com http://training.figleaf.com ___ Flashcoders@chattyfig.figleaf.com To change your subscription options or search the archive: http://chattyfig.figleaf.com/mailman/listinfo/flashcoders Brought to you by Fig Leaf Software Premier Authorized Adobe Consulting and Training http://www.figleaf.com http://training.figleaf.com
Re: [Flashcoders] Area of a triangle using perimiter values only
Hello Jason,
public function getTriangleArea (a:Number, b:Number, c:Number):Number {
var p:Number = (a+b+c)/2;
return Math.sqrt(p*(p-a)*(p-b)*(p-c));
}
--
Ivan Dembicki
__
[EMAIL PROTECTED] | http://www.artlebedev.ru | http://www.sharedfonts.com
___
Flashcoders@chattyfig.figleaf.com
To change your subscription options or search the archive:
http://chattyfig.figleaf.com/mailman/listinfo/flashcoders
Brought to you by Fig Leaf Software
Premier Authorized Adobe Consulting and Training
http://www.figleaf.com
http://training.figleaf.com
Re: Re: [Flashcoders] Area of a triangle using perimiter values only
Jason,
It must be true that your inputs are incorrect, BUT to answer your
question about distributive methods - I was just thinking about
condensing that formula. If you did that(and they do it in the next
step on the MathWorld link) then you have to multiply every term in
parens by every other term in parens and you get all of that whacky
a^4, b^4 business. As it is, you're supplying your function with the
values of a, b, and c, so you can add them in the parens and multiply
out the whole numbers. False alarm there!
Cheers
On 12/14/06, Nex Ninek [EMAIL PROTECTED] wrote:
Negative result of ((a+b+c)*(b+c-a)*(c+a-b)*(a+b-c)) is not possible if a,b,
and c are lengths of a triangle's sides. The first term will always be
obviously positive, and so will the other three terms -- they are simply
the sum of the lengths of two sides less the third side, and you can't have
a triangle where that isn't true. It's most likely that your input numbers
to the formula are incorrect. Trace that to find your problem.
On 12/14/06, Merrill, Jason [EMAIL PROTECTED] wrote:
I'm trying to figure the area of a triangle in Actionscript using the
perimeter values only, not the traditional simple formula:
area = (height/2)*base
because figuring the height is tricky given the triangle will be drawn
in odd ways (i.e. a not horizontally alinged base), so I am exploring
other triangle area forumulas that only take in the perimiter values
(a,b,c), like Heron's formula or this one, which I like:
given a,b,c are the length of the sides of the triangle, then the
formula is:
squareRoot of: (a+b+c)(b+c-a)(c+a-b)(a+b-c)
___
4
So in trying to translate that to actionscript, I wrote:
public static function areaOfTriangle(a:Number, b:Number,
c:Number):Number{
return (Math.sqrt((a+b+c)*(b+c-a)*(c+a-b)*(a+b-c)))/4;
}
But the problem is (a+b+c)*(b+c-a)*(c+a-b)*(a+b-c) results in a negative
number, and this the square root cannot be taken. Or perhaps I am
interpreting the forumula incorrectly:
http://mathworld.wolfram.com/TriangleArea.html
What am I doing wrong here? Thanks.
Jason Merrill
Bank of America
Learning Organizational Effectiveness
___
Flashcoders@chattyfig.figleaf.com
To change your subscription options or search the archive:
http://chattyfig.figleaf.com/mailman/listinfo/flashcoders
Brought to you by Fig Leaf Software
Premier Authorized Adobe Consulting and Training
http://www.figleaf.com
http://training.figleaf.com
___
Flashcoders@chattyfig.figleaf.com
To change your subscription options or search the archive:
http://chattyfig.figleaf.com/mailman/listinfo/flashcoders
Brought to you by Fig Leaf Software
Premier Authorized Adobe Consulting and Training
http://www.figleaf.com
http://training.figleaf.com
--
Jordan Snyder
Applications Developer
Image Action LLC
http://www.imageaction.com
___
Flashcoders@chattyfig.figleaf.com
To change your subscription options or search the archive:
http://chattyfig.figleaf.com/mailman/listinfo/flashcoders
Brought to you by Fig Leaf Software
Premier Authorized Adobe Consulting and Training
http://www.figleaf.com
http://training.figleaf.com
Re: [Flashcoders] Area of a triangle using perimiter values only
Heron's formula looks pretty simple:
function triangleArea(a:Number, b:Number, c:Number):Number {
// Check that all arguments are positive and finite.
if (!(a 0) || !(b 0) || !(c 0) || !isFinite(a) ||
!isFinite(b) || !isFinite(c)) {
throw new Error(Invalid argument(s) for triangleArea: +
arguments.join(, ));
}
// Calculate semiperimeter.
var s:Number = (a + b + c) / 2;
// Calculate and return area using Heron's formula.
return Math.sqrt(s * (s - a) * (s - b) * (s - c));
}
--
T. Michael Keesey
Director of Technology
Exopolis, Inc.
2894 Rowena Avenue Ste. B
Los Angeles, California 90039
--
The Dinosauricon: http://dino.lm.com
Parry Carney: http://parryandcarney.com
ISPN Forum: http://www.phylonames.org/forum/
___
Flashcoders@chattyfig.figleaf.com
To change your subscription options or search the archive:
http://chattyfig.figleaf.com/mailman/listinfo/flashcoders
Brought to you by Fig Leaf Software
Premier Authorized Adobe Consulting and Training
http://www.figleaf.com
http://training.figleaf.com
Re[2]: [Flashcoders] Area of a triangle using perimiter values only
Hello, TMK Actually, this does return NaN for some numbers, but it's pretty TMK simple to realize why. For example, it returns NaN if you input side TMK lengths of 1, 2, 4. - it is not triangle. -- Ivan Dembicki [EMAIL PROTECTED] || http://www.design.ru ___ Flashcoders@chattyfig.figleaf.com To change your subscription options or search the archive: http://chattyfig.figleaf.com/mailman/listinfo/flashcoders Brought to you by Fig Leaf Software Premier Authorized Adobe Consulting and Training http://www.figleaf.com http://training.figleaf.com
RE: [Flashcoders] Area of a triangle using perimiter values only
Thanks - all, yes Jake saw it first and others chimed in with the same
thought, my numbers did not compute because they did not make a
triangle. I have it working now.
The formula is fine, and this function works for me as long as the
values come from a true triangle:
public static function areaOfTriangle(a:Number, b:Number,
c:Number):Number{
return (Math.sqrt((a+b+c)*(b+c-a)*(c+a-b)*(a+b-c)))/4;
}
Thanks eveyrone!
Jason Merrill
Bank of America
Learning Organizational Effectiveness
___
Flashcoders@chattyfig.figleaf.com
To change your subscription options or search the archive:
http://chattyfig.figleaf.com/mailman/listinfo/flashcoders
Brought to you by Fig Leaf Software
Premier Authorized Adobe Consulting and Training
http://www.figleaf.com
http://training.figleaf.com
RE: [Flashcoders] Area of a triangle using perimiter values only
) ) {
angleC =
Math.acos((Math.pow(a,2)+Math.pow(b,2)-Math.pow(c,2))/2*a*b);
return angle;
} else if ( (c == undefined) || (c == null) ) {
c =
Math.sqrt(Math.pow(a,2)+Math.pow(b,2)-2*a*b*Math.cos(angleC));
return c;
}
}
//
/***
**
*
* Method : angleRule
*
* Refers to the angle rule
* angleC + angleA + angleB = 180
*
* @param : angleA - the angle opposed to the a side
*angleB - the angle opposed to the b
side
*
*/
//
public static function angleRule(angleA:Number,
angleB:Number):Number {
var angleC:Number;
angleC = 180 - (angleA + angleB);
return angleC;
}
//
/***
**
*
* Method : area
*
* Calculates the area of a triangle (best for a rectangle
triangle)
* A = b*h/2
*
* @param : b - the base of the triangle
*h - the height of the triangle
*
*/
//
public static function area(b:Number, h:Number):Number {
var area:Number;
area = b*h/2;
return area;
}
//
/***
**
*
* Method : areaHeron
*
* Calculates the area of a triangle where s is the triangle's
semiperimeter
* s = a+b+c/2
* A = sqrt(s(s-a)(s-b)(s-c))
*
* @param : a - the a side
*b - the b side
*c - the c side
*
*/
//
public static function areaHeron(a:Number, b:Number,
c:Number):Number {
var area:Number;
area = Math.sqrt((a+b+c)*(a+b-c)*(b+c-a)*(c+a-c))/4;
return area;
}
}
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Merrill,
Jason
Sent: 14 décembre 2006 14:06
To: Flashcoders mailing list
Subject: RE: [Flashcoders] Area of a triangle using perimiter values only
Thanks - all, yes Jake saw it first and others chimed in with the same
thought, my numbers did not compute because they did not make a triangle. I
have it working now.
The formula is fine, and this function works for me as long as the values
come from a true triangle:
public static function areaOfTriangle(a:Number, b:Number,
c:Number):Number{
return (Math.sqrt((a+b+c)*(b+c-a)*(c+a-b)*(a+b-c)))/4;
}
Thanks eveyrone!
Jason Merrill
Bank of America
Learning Organizational Effectiveness
___
Flashcoders@chattyfig.figleaf.com
To change your subscription options or search the archive:
http://chattyfig.figleaf.com/mailman/listinfo/flashcoders
Brought to you by Fig Leaf Software
Premier Authorized Adobe Consulting and Training http://www.figleaf.com
http://training.figleaf.com
--
No virus found in this incoming message.
Checked by AVG Free Edition.
Version: 7.1.409 / Virus Database: 268.15.18/586 - Release Date: 2006-12-13
--
No virus found in this outgoing message.
Checked by AVG Free Edition.
Version: 7.1.409 / Virus Database: 268.15.18/586 - Release Date: 2006-12-13
___
Flashcoders@chattyfig.figleaf.com
To change your subscription options or search the archive:
http://chattyfig.figleaf.com/mailman/listinfo/flashcoders
Brought to you by Fig Leaf Software
Premier Authorized Adobe Consulting and Training
http://www.figleaf.com
http://training.figleaf.com
Re: RE: [Flashcoders] Area of a triangle using perimiter values only
)-Math.pow(c,2))/2*a*b);
return angle;
} else if ( (c == undefined) || (c == null) ) {
c =
Math.sqrt(Math.pow(a,2)+Math.pow(b,2)-2*a*b*Math.cos(angleC));
return c;
}
}
//
/***
**
*
* Method : angleRule
*
* Refers to the angle rule
* angleC + angleA + angleB = 180
*
* @param : angleA - the angle opposed to the a side
*angleB - the angle opposed to the b
side
*
*/
//
public static function angleRule(angleA:Number,
angleB:Number):Number {
var angleC:Number;
angleC = 180 - (angleA + angleB);
return angleC;
}
//
/***
**
*
* Method : area
*
* Calculates the area of a triangle (best for a rectangle
triangle)
* A = b*h/2
*
* @param : b - the base of the triangle
*h - the height of the triangle
*
*/
//
public static function area(b:Number, h:Number):Number {
var area:Number;
area = b*h/2;
return area;
}
//
/***
**
*
* Method : areaHeron
*
* Calculates the area of a triangle where s is the triangle's
semiperimeter
* s = a+b+c/2
* A = sqrt(s(s-a)(s-b)(s-c))
*
* @param : a - the a side
*b - the b side
*c - the c side
*
*/
//
public static function areaHeron(a:Number, b:Number,
c:Number):Number {
var area:Number;
area = Math.sqrt((a+b+c)*(a+b-c)*(b+c-a)*(c+a-c))/4;
return area;
}
}
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Merrill,
Jason
Sent: 14 décembre 2006 14:06
To: Flashcoders mailing list
Subject: RE: [Flashcoders] Area of a triangle using perimiter values only
Thanks - all, yes Jake saw it first and others chimed in with the same
thought, my numbers did not compute because they did not make a triangle. I
have it working now.
The formula is fine, and this function works for me as long as the values
come from a true triangle:
public static function areaOfTriangle(a:Number, b:Number,
c:Number):Number{
return (Math.sqrt((a+b+c)*(b+c-a)*(c+a-b)*(a+b-c)))/4;
}
Thanks eveyrone!
Jason Merrill
Bank of America
Learning Organizational Effectiveness
___
Flashcoders@chattyfig.figleaf.com
To change your subscription options or search the archive:
http://chattyfig.figleaf.com/mailman/listinfo/flashcoders
Brought to you by Fig Leaf Software
Premier Authorized Adobe Consulting and Training http://www.figleaf.com
http://training.figleaf.com
--
No virus found in this incoming message.
Checked by AVG Free Edition.
Version: 7.1.409 / Virus Database: 268.15.18/586 - Release Date: 2006-12-13
--
No virus found in this outgoing message.
Checked by AVG Free Edition.
Version: 7.1.409 / Virus Database: 268.15.18/586 - Release Date: 2006-12-13
___
Flashcoders@chattyfig.figleaf.com
To change your subscription options or search the archive:
http://chattyfig.figleaf.com/mailman/listinfo/flashcoders
Brought to you by Fig Leaf Software
Premier Authorized Adobe Consulting and Training
http://www.figleaf.com
http://training.figleaf.com
--
Jordan Snyder
Applications Developer
Image Action LLC
http://www.imageaction.com
___
Flashcoders@chattyfig.figleaf.com
To change your subscription options or search the archive:
http://chattyfig.figleaf.com/mailman/listinfo/flashcoders
Brought to you by Fig Leaf Software
Premier Authorized Adobe Consulting and Training
http://www.figleaf.com
http://training.figleaf.com
