Subject:
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Re: How to make a perfect octagon or hexagon?
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Newsgroups:
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lugnet.technic, lugnet.edu
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Followup-To:
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lugnet.edu
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Date:
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Mon, 10 Dec 2007 16:32:51 GMT
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Viewed:
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1627 times
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In lugnet.technic, Joe Strout wrote:
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I’m trying to make a largish... octagon or hexagon out of
technic parts.
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A 12-12-17 triangle is very nearly right, and has angles of about 44.9 degrees.
I used four of them in making a stop sign:
Note that all eight corners are nicely studded down.
Joe and Brian wrote:
Well whaddaya know! I’d always assumed those things were 135 degrees. Looks
like I learned something today. Brian, many thanks for the terrific Lego
geometry links I did not know about. You made my day.
Brian Davis wrote:
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The internal angles on a 3-4-5 right triangle are 30, 60, and of course 90
degrees.
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And now a teachable moment! You’ve made my week! As DaveE alludes elsewhere in
this thread, a 3-4-5 triangle has angles of about 36.87, 53.13, and 90 degrees.
Making one of these triangles is a great way to build a strong right angle. A
triangle with angles of 30, 60, and 90 degrees is a different animal: half an
equilateral triangle. It can help in making a regular hexagon. Unfortunately,
at least one of its sides must have a funny (irrational) length, so it isn’t the
easiest thing to build in brick or technic.
-Teddy
p.s. I must admit that when I first read Brian’s statement, I made a noise so
horrible my colleagues here in the math department wondered if I was ill. Don’t
worry. I’ll be fine. Eventually.
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Message has 1 Reply:
 | | Re: How to make a perfect octagon or hexagon?
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| (...) Yeah, about 5 minutes after I submitted that I realized just how stupid I've become as of late (I plead mercy due to a very nasty sinus infection... but dang it, I should have caught that even if I was unconcious). What will make it even (...) (17 years ago, 10-Dec-07, to lugnet.edu)
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Message is in Reply To:
| | Re: How to make a perfect octagon or hexagon?
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| (...) Try approaching it in steps. Can you make an equilateral triangle out of Technic beams? Don't worry about making the angles rigid, just make a structure with three equal-length sides, connected near the corners (connected with something that (...) (17 years ago, 10-Dec-07, to lugnet.technic)
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