

Subject:
Sum of the angles of a tetrahedron in steradians  for pafalafa
Category: Science > Math Asked by: jeffsmithga List Price: $10.00 
Posted:
12 Aug 2005 07:14 PDT
Expires: 16 Aug 2005 08:40 PDT Question ID: 554911 
What is the value, in steradians, of the sum of the solid internal angles of a random tetrahedron (as an analodue to the sum of the internal angles of a random triangle being 2*pi radians)? Or is that sum not constant? I'm pricing this at just 10 dollars but I will give a handsome tip if you provide quite a good reply. Maybe you might be interested in the question yourself. js  
 
 
 


There is no answer at this time. 

Subject:
Re: Sum of the angles of a tetrahedron in steradians  for pafalafa
From: racecarga on 12 Aug 2005 13:18 PDT 
http://answers.google.com/answers/threadview?id=160247 12*arccos(1/3) 
Subject:
Re: Sum of the angles of a tetrahedron in steradians  for pafalafa
From: racecarga on 12 Aug 2005 13:23 PDT 
That is for a regular tetrahedron. The sum is different for different tetrahedrons. You can see this by taking the limit of a very flat tetrahedron. One vertex approaches a solid angle of 2pi, the other 3 approach zero, so the sum of the solid angles tends toward 2pi, which is different from the value for a regular tetrahedron. 
Subject:
Re: Sum of the angles of a tetrahedron in steradians  for pafalafa
From: jeffsmithga on 12 Aug 2005 14:39 PDT 
Thank you for answering. This pretty much covers it. I guess it is worth something, too, so expect a 2 dollar question from me. js 
Subject:
Re: Sum of the angles of a tetrahedron in steradians  for pafalafa
From: pinkfreudga on 12 Aug 2005 14:44 PDT 
Jeff, Racecar isn't a Google Answers Researcher, so his assistance isn't compensable. Looks as if you've gotten a nice freebie from one of the site's most helpful users! ~Pink 
Subject:
Re: Sum of the angles of a tetrahedron in steradians  for pafalafa
From: jeffsmithga on 12 Aug 2005 16:32 PDT 
Sorry about racecar. Having trouble with my eyesight lately. And I thought I would age gracefully! 
Subject:
Re: Sum of the angles of a tetrahedron in steradians  for pafalafa
From: racecarga on 15 Aug 2005 00:23 PDT 
Hi jeffsmithga, Glad my comment was helpful. As you can see, I was interested in the same question a while back. 
Subject:
Re: Sum of the angles of a tetrahedron in steradians  for pafalafa
From: jeffsmithga on 15 Aug 2005 08:12 PDT 
Hi racecar. I take this question, when posed, to be one of the true marks of an inquiring mind (especially if the questioner has not studied Mathematics). Sorry again for mixing you up with a Google researcher. js (Dimitri B.) 
Subject:
Re: Sum of the angles of a tetrahedron in steradians  for pafalafa
From: jeffsmithga on 16 Aug 2005 07:01 PDT 
Since pafalafa has apparently disdained to give just any sort of answer to this question and collect 10 dollars, I will presently cancel this question. js (Dimitri B.) 
Subject:
Re: Sum of the angles of a tetrahedron in steradians  for pafalafa
From: pafalafaga on 16 Aug 2005 07:09 PDT 
Hi Jeff (or is it Dimitri?). First off, I never properly thanked you for steering this question to my attention. So....Thanks! I hope you don't feel I'm ignoring you. But I certainly don't feel I can post an answer to a question that...well...I haven't answered (and don't really feel competent to answer). So, I've just left the question here, content that you seem to have gotten the answer you need from the comments section. Hope to see you again one of these days. paf 
Subject:
Re: Sum of the angles of a tetrahedron in steradians  for pafalafa
From: jeffsmithga on 16 Aug 2005 08:40 PDT 
Ok, paf, I suppose that's clear enough. Thank YOU for taking the time to post yet another comment. I will now retire the question. D.B. 
If you feel that you have found inappropriate content, please let us know by emailing us at answerssupport@google.com with the question ID listed above. Thank you. 
Search Google Answers for 
Google Home  Answers FAQ  Terms of Service  Privacy Policy 