Telescoping series: Difference between revisions
en>DannyAsher |
|||
| Line 1: | Line 1: | ||
{{Even polygon db|Even polygon stat table|p12}} | |||
In [[geometry]], a '''dodecagon''' is any [[polygon]] with [[12 (number)|twelve]] sides and twelve [[angle]]s. | |||
==Regular dodecagon== | |||
A [[regular polygon|regular]] dodecagon has all sides of equal length and all angles equal to 150°. It has 12 lines of symmetry and rotational symmetry of order 12. Its [[Schläfli symbol]] is {12}. | |||
The [[area]] of a regular dodecagon with side ''a'' is given by: | |||
:<math>\begin{align} A & = 3 \cot\left(\frac{\pi}{12} \right) a^2 = | |||
3 \left(2+\sqrt{3} \right) a^2 \\ | |||
& \simeq 11.19615242\,a^2. | |||
\end{align}</math> | |||
Or, if ''R'' is the radius of the [[circumscribe]]d circle,<ref>See also [[József Kürschák|Kürschák]]'s geometric proof on [http://demonstrations.wolfram.com/KurschaksDodecagon/ the Wolfram Demonstration Project]</ref> | |||
:<math>A = 6 \sin\left(\frac{\pi}{6}\right) R^2 = 3 R^2.</math> | |||
And, if ''r'' is the radius of the [[inscribe]]d circle, | |||
:<math>\begin{align} A & = 12 \tan\left(\frac{\pi}{12}\right) r^2 = | |||
12 \left(2-\sqrt{3} \right) r^2 \\ | |||
& \simeq 3.2153903\,r^2. | |||
\end{align}</math> | |||
A simple formula for area (given the two measurements) is: <math>\scriptstyle A\,=\,3ad</math> where ''d'' is the distance between parallel sides. | |||
Length ''d'' is the height of the dodecahedron when it sits on a side as base, and the diameter of the inscribed circle. | |||
By simple trigonometry, <math>\scriptstyle d\,=\,a(1\,+\,2cos{30^\circ}\,+\,2cos{60^\circ})</math>. | |||
== Uses == | |||
A regular dodecagon can fill a plane vertex with other regular polygons: | |||
{| class=wikitable | |||
|[[File:3.12.12 vertex.png|120px]]<BR>3.12.12 | |||
|[[File:4.6.12 vertex.png|120px]]<BR>4.6.12 | |||
|[[File:3.3.4.12 vertex.png|120px]]<BR>3.3.4.12 | |||
|[[File:3.4.3.12 vertex.png|120px]]<BR>3.4.3.12 | |||
|} | |||
==Dodecagon construction== | |||
A regular dodecagon is [[constructible polygon|constructible]] using [[compass and straightedge]]: | |||
[[File:Regular Dodecagon Inscribed in a Circle.gif]]<br>Construction of a regular dodecagon | |||
==Occurrence== | |||
===Tiling=== | |||
Here are 3 example [[Tiling by regular polygons|periodic plane tilings]] that use dodecagons: | |||
{| width=640 class="wikitable" | |||
|[[Image:Tile 3bb.svg|205px|Tile 3bb.svg]]<br>[[Truncated hexagonal tiling|Semiregular tiling 3.12.12]] | |||
|[[Image:Tile 46b.svg|205px]]<br>[[Great rhombitrihexagonal tiling|Semiregular tiling: 4.6.12]] | |||
|[[Image:Dem3343tbc.gif|205px]]<br>A [[Tilings of regular polygons#Other edge-to-edge tilings|demiregular tiling]]:<br>3.3.4.12 & 3.3.3.3.3.3 | |||
|} | |||
===Pattern blocks=== | |||
[[File:Wooden pattern blocks dodecagon.JPG||thumb|Dodecagon made with [[pattern blocks]]]] | |||
One of the ways the [[mathematical manipulative]] [[pattern blocks]] are used is in creating a number of different dodecagons.<ref>"Doin' Da' Dodeca'" on [http://mathforum.org/berman/patternblocks/classics/responses/chal2/doin_da_dodeca.html mathforum.org]</ref> | |||
===Petrie polygons=== | |||
The regular dodecagon is the [[Petrie polygon]] for many higher dimensional polytopes, seen as [[orthogonal projection]]s in [[Coxeter plane]]s, including: | |||
{| class=wikitable width=540 | |||
|- align=center valign=top | |||
!valign=center|A<sub>11</sub> | |||
|[[File:11-simplex_t0.svg|100px]]<br>[[11-simplex]] | |||
|[[File:11-simplex_t1.svg|100px]]<br>[[Rectified 11-simplex]] | |||
|[[File:11-simplex_t2.svg|100px]]<br>[[Birectified 11-simplex]] | |||
|[[File:11-simplex_t3.svg|100px]]<br>[[Trirectified 11-simplex]] | |||
|[[File:11-simplex_t4.svg|100px]]<br>[[Quadrirectified 11-simplex]] | |||
|[[File:11-simplex_t5.svg|100px]]<br>[[Quintirectified 11-simplex]] | |||
|- align=center valign=top | |||
!valign=center|BC<sub>6</sub> | |||
|[[File:6-cube_t5.svg|100px]]<br>[[6-orthoplex]] | |||
|[[File:6-cube_t4.svg|100px]]<br>[[Rectified 6-orthoplex]] | |||
|[[File:6-cube_t3.svg|100px]]<br>[[Birectified 6-orthoplex]] | |||
|[[File:6-cube_t2.svg|100px]]<br>[[Birectified 6-cube]] | |||
|[[File:6-cube_t1.svg|100px]]<br>[[Rectified 6-cube]] | |||
|[[File:6-cube_t0.svg|100px]]<br>[[6-cube]] | |||
|- align=center valign=top | |||
!valign=center|D<sub>7</sub> | |||
|[[File:7-cube_t6_B6.svg|100px]]<br>[[7-orthoplex|t<sub>5</sub>(1<sub>41</sub>)]] | |||
|[[File:7-cube_t5_B6.svg|100px]]<br>[[Rectified 7-orthoplex|t<sub>4</sub>(1<sub>41</sub>)]] | |||
|[[File:7-cube_t4_B6.svg|100px]]<br>[[Birectified 7-orthoplex|t<sub>3</sub>(1<sub>41</sub>)]] | |||
|[[File:7-cube_t3_B6.svg|100px]]<br>[[Birectified 7-cube|t<sub>2</sub>(1<sub>41</sub>)]] | |||
|[[File:7-demicube_t1_D7.svg|100px]]<br>[[Rectified 7-cube|t<sub>1</sub>(1<sub>41</sub>)]] | |||
|[[File:7-demicube_t0_D7.svg|100px]]<br>[[7-demicube|t<sub>0</sub>(1<sub>41</sub>)]] | |||
|- align=center valign=top | |||
!valign=center|[[E6 (mathematics)|E<sub>6</sub>]] | |||
|[[File:E6 graph.svg|100px]]<br>[[2 21 polytope|t<sub>0</sub>(2<sub>21</sub>)]] | |||
|[[File:Up 2 21 t1 E6.svg|100px]]<br>t<sub>1</sub>(2<sub>21</sub>) | |||
|[[File:Up 2 21 t2 E6.svg|100px]]<br>t<sub>1</sub>(1<sub>22</sub>) | |||
|[[File:Gosset 1 22 polytope.png|100px]]<br>[[1 22 polytope|t<sub>0</sub>(1<sub>22</sub>)]] | |||
|- align=center valign=top | |||
!valign=center|[[F4 (mathematics)|F<sub>4</sub>]] | |||
|[[File:24-cell_t0_F4.svg|100px]]<br>[[24-cell]] | |||
|[[File:24-cell_t1_F4.svg|100px]]<br>[[Rectified 24-cell]] | |||
|[[File:24-cell h01 F4.svg|100px]]<br>[[Snub 24-cell]] | |||
|} | |||
==Examples in use== | |||
In [[block capitals]], the letters [[E]], [[H]] and [[X]] (and [[I]] in a [[slab serif]] font) have dodecagonal outlines. | |||
[[File:Segovia Vera Cruz.jpg|thumb|The Vera Cruz church in [[Segovia]]]] | |||
The regular dodecagon features prominently in many buildings. The [[Torre del Oro]] is a dodecagonal military [[Watchtower (fortification)|watchtower]] in [[Seville]], southern [[Spain]], built by the [[Almohad dynasty]]. The early thirteenth century Vera Cruz church in [[Segovia]], Spain is dodecagonal. Another example is the Porta di Venere (Venus' Gate), in [[Spello]], [[Italy]], built in the 1st century BC has two dodecagonal towers, called "Propertius' Towers". | |||
[[File:1942 threepence reverse.jpg|thumb|A 1942 British threepence, reverse]] | |||
Regular dodecagonal coins include: | |||
*[[Threepence (British coin)|British threepenny bit]] from 1937 to 1971, when it ceased to be legal tender. | |||
*[[Australian 50-cent coin]] | |||
*[[Coins of the Fijian dollar|Fijian 50 cents]] | |||
*[[Tongan paʻanga|Tongan 50-seniti]], since 1974 | |||
*[[Solomon Islands dollar|Solomon Islands 50 cents]] | |||
*[[Croatian kuna|Croatian 25 kuna]] | |||
*[[Romanian leu|Romanian 5000 lei]], 2001–2005 | |||
*[[Penny (Canadian coin)|Canadian penny]], 1982–1996 | |||
*[[South Vietnamese đồng|South Vietnamese 25 đồng]], 1968–1975 | |||
*[[Zambian kwacha|Zambian 50 ngwee]], 1969–1992 | |||
*[[Malawian kwacha|Malawian 50 tambala]], 1986–1995 | |||
*[[Mexican peso|Mexican 20 centavos]], since 1992 | |||
==See also== | |||
*[[Dodecagonal number]] | |||
*[[Dodecahedron]] – a regular [[polyhedron]] with 12 [[pentagon]]al faces. | |||
*[[Dodecagram]] | |||
==Notes== | |||
{{Reflist}} | |||
==External links== | |||
*{{MathWorld |urlname=Dodecagon |title=Dodecagon}} | |||
*[http://www.cut-the-knot.org/Curriculum/Geometry/KurschakTile.shtml Kürschak's Tile and Theorem] | |||
*[http://www.mathopenref.com/dodecagon.html Definition and properties of a dodecagon] With interactive animation | |||
{{Polygons}} | |||
[[Category:Polygons]] | |||
Revision as of 00:33, 7 December 2013
My name is Madelaine and I am studying Industrial and Labor Relations and Continuing Education and Summer Sessions at Kleindorf Ii / Austria.
my web site: fitness exercise programs
In geometry, a dodecagon is any polygon with twelve sides and twelve angles.
Regular dodecagon
A regular dodecagon has all sides of equal length and all angles equal to 150°. It has 12 lines of symmetry and rotational symmetry of order 12. Its Schläfli symbol is {12}.
The area of a regular dodecagon with side a is given by:
Or, if R is the radius of the circumscribed circle,[1]
And, if r is the radius of the inscribed circle,
A simple formula for area (given the two measurements) is: where d is the distance between parallel sides.
Length d is the height of the dodecahedron when it sits on a side as base, and the diameter of the inscribed circle.
Uses
A regular dodecagon can fill a plane vertex with other regular polygons:
3.12.12 |
4.6.12 |
3.3.4.12 |
3.4.3.12 |
Dodecagon construction
A regular dodecagon is constructible using compass and straightedge:

Construction of a regular dodecagon
Occurrence
Tiling
Here are 3 example periodic plane tilings that use dodecagons:
Semiregular tiling 3.12.12 |
Semiregular tiling: 4.6.12 |
A demiregular tiling: 3.3.4.12 & 3.3.3.3.3.3 |
Pattern blocks
One of the ways the mathematical manipulative pattern blocks are used is in creating a number of different dodecagons.[2]
Petrie polygons
The regular dodecagon is the Petrie polygon for many higher dimensional polytopes, seen as orthogonal projections in Coxeter planes, including:
Examples in use
In block capitals, the letters E, H and X (and I in a slab serif font) have dodecagonal outlines.
The regular dodecagon features prominently in many buildings. The Torre del Oro is a dodecagonal military watchtower in Seville, southern Spain, built by the Almohad dynasty. The early thirteenth century Vera Cruz church in Segovia, Spain is dodecagonal. Another example is the Porta di Venere (Venus' Gate), in Spello, Italy, built in the 1st century BC has two dodecagonal towers, called "Propertius' Towers".
Regular dodecagonal coins include:
- British threepenny bit from 1937 to 1971, when it ceased to be legal tender.
- Australian 50-cent coin
- Fijian 50 cents
- Tongan 50-seniti, since 1974
- Solomon Islands 50 cents
- Croatian 25 kuna
- Romanian 5000 lei, 2001–2005
- Canadian penny, 1982–1996
- South Vietnamese 25 đồng, 1968–1975
- Zambian 50 ngwee, 1969–1992
- Malawian 50 tambala, 1986–1995
- Mexican 20 centavos, since 1992
See also
- Dodecagonal number
- Dodecahedron – a regular polyhedron with 12 pentagonal faces.
- Dodecagram
Notes
43 year old Petroleum Engineer Harry from Deep River, usually spends time with hobbies and interests like renting movies, property developers in singapore new condominium and vehicle racing. Constantly enjoys going to destinations like Camino Real de Tierra Adentro.
External links
I had like 17 domains hosted on single account, and never had any special troubles. If you are not happy with the service you will get your money back with in 45 days, that's guaranteed. But the Search Engine utility inside the Hostgator account furnished an instant score for my launched website. Fantastico is unable to install WordPress in a directory which already have any file i.e to install WordPress using Fantastico the destination directory must be empty and it should not have any previous installation files. When you share great information, others will take note. Once your hosting is purchased, you will need to setup your domain name to point to your hosting. Money Back: All accounts of Hostgator come with a 45 day money back guarantee. If you have any queries relating to where by and how to use Hostgator Discount Coupon, you can make contact with us at our site. If you are starting up a website or don't have too much website traffic coming your way, a shared plan is more than enough. Condition you want to take advantage of the worldwide web you prerequisite a HostGator web page, -1 of the most trusted and unfailing web suppliers on the world wide web today. Since, single server is shared by 700 to 800 websites, you cannot expect much speed.
Hostgator tutorials on how to install Wordpress need not be complicated, especially when you will be dealing with a web hosting service that is friendly for novice webmasters and a blogging platform that is as intuitive as riding a bike. After that you can get Hostgator to host your domain and use the wordpress to do the blogging. Once you start site flipping, trust me you will not be able to stop. I cut my webmaster teeth on Control Panel many years ago, but since had left for other hosting companies with more commercial (cough, cough) interfaces. If you don't like it, you can chalk it up to experience and go on. First, find a good starter template design. When I signed up, I did a search for current "HostGator codes" on the web, which enabled me to receive a one-word entry for a discount. Your posts, comments, and pictures will all be imported into your new WordPress blog.- Kürschak's Tile and Theorem
- Definition and properties of a dodecagon With interactive animation
Hostgator Discounts - http://support.borinquenhealth.org/entries/32309034-Hostgator-Iran. Hostgator is a large privately possessed hosting business running from numerous state of the art facilities in Dallas, Texas. Hostgator was founded in 2002, since then they have actually proliferated and currently host over 400,000 websites. They are also commonly thought about to be the worlds leading carrier of reseller hosting accounts. At present they provide hosting to over 10,000 individual reseller account consumers.
Hostgator provides numerous various webhosting plans, and deal with a broad range of clients. From the first time web designer who requires basic, tension cost-free hosting for their personal site; all the means with to huge corporations, who need specialist dedicated hosting services.
Hostgator's hosting packages can be divided into 3 teams; standard shared hosting strategies (ideal for the huge majority individuals), reseller hosting strategies (these are primarily for people and companies that want to "resell" their account resources to clients of their own), and lastly committed server plans (these accounts provide customer their own server, so they do not need to share its resources with anyone else). Extremely few of us will every need a devoted server so this evaluation will focus on the shared hosting strategies that Hostgator offer.
Attributes
Hostgator's three primary shared hosting strategies are named: "Hatchling" (the entry level plan priced at $6.95 / month), "Child" (this is the most popular strategy, and it is likely to please the requirements of a very broad array of customers), and "Swamp" (similar as the "Child" plan, however with boosts in bandwidth and disk space, priced at $14.95 / month).
For a full list of functions and a side by side comparison of all hosting strategies you must see Hostgator's internet site below. Below is a testimonial of the most essential features of the "Baby" plan, this is most likely the most suitable package for most users, and it is our favored plan.
Disk space 100GB - This amount has actually been just recently updated by Hostgator from 5GB to a huge 100GB. All individuals are most likely to discover it impossible to tire this amount of disk area.
Bandwidth 1000GB/month - Likewise increased is the bandwidth allocation, from 75GB to an apparently extreme 1000GB. Again virtually no chance of utilizing all that, but it's nice to know that you definitely will not be dealing with additional charges for reviewing your restriction, even if you have a very busy website(s).
Site Studio website home builder - This is an excellent free of cost program that allows you to build your website from scratch. You have over 500 design templates and color design to pick from. You need no HTML experience, or code writing knowledge. It provides the easiest possible way of designing an expert looking website in an extremely brief space of time. Nevertheless, there is no should take my word for it, as Hostgator provides us with a trial variation of the software on their internet site!
Endless add-on domains - This really is the stand out feature of this hosting plan (the "Hatchling" strategy just allows 1 domain), and allows you to host as numerous internet sites as you like on a single account, at no extra expense. This allows you to make full use of your large bandwidth and disk space allowances, and host multiple websites at a fraction of the normal cost.
99.9 % Uptime assurance - This basically informs us that Hostgator is a major host providing a dependable service. If uptime drops below this figure in any provided month then you do not spend for that months hosting, it's as simple as that! We would never think about making use of a host that did not offer a strong uptime guarantee; this is simply because there is just one good reason a host will not provide an uptime assurance - undependable uptime!
30 Day refund guarantee - This has become a rather conventional feature in the webhosting neighborhood, though it's good to have for included assurance.
Instantaneous setup - Many hosting carriers take 24-48 hours to setup your account however Hostgator guarantees to have you up and running in under 15 minutes (they do not charge a setup fee either)!
Limitless MySQL data sources - This is really beneficial since each Fantastico (see below) script needs its own MySQL database.
Fantastico DeLuxe - This outstanding program permits you to immediately set up over 50 scripts through your control panel. Scripts include blogs, online forums, galleries, shopping carts, and more.
Unrestricted e-mail accounts - Permits you to have as numerous, or as couple of, various email addresses as you like.
cPanel control board - At the heart of any hosting experience is the control panel, the good news is Hostgator uses one of the very best systems around, a cPanel. It's well laid out and easy to operate. It consists of numerous features and provides excellent efficiency. Best of all, there is a full working trial on the Hostgator website, so you can test it out yourself!
Customer support and technical support
Hostgator gives us 24/7 phone support, and live online chat. The truth that you are offered 2 options to receive instantaneous technical support at any time of the day is wonderful. Our experience has actually constantly been excellent when contacting Hostgator, their operatives are really polite and most notably they appear to understand their stuff when taking care of technical concerns. However, we always suggest contacting them yourself prior to signing up. Ask a concern and see if you're thrilled by their feedback. This constantly informs you a lot about a company!
Efficiency
The performance from Hostgator's servers is excellent! Hostgator location much tighter limits on the variety of sites sharing the same server compared with most various other shared hosting providers. This offers higher dependability because less strain is put on the servers; and it likewise greatly improves the speed at which your web pages run.
Server efficiency is another one of the vital locations where Hostgator identify themselves from the crowd of various other webhosting.
Our judgment
Overall there is so much to like about the means Hostgator does company, they truly do appear to have a great grasp on exactly what the typical customer needs from an internet hosting provider. Hardly ever do you come across reports of dissatisfied Hostgator customers, and after hosting with them ourselves we now know why! At simply $9.95 / month for the "Child" strategy (which consists of unrestricted domains); anyone looking to host even more than one website has a pretty simple choice to make.
- ↑ See also Kürschák's geometric proof on the Wolfram Demonstration Project
- ↑ "Doin' Da' Dodeca'" on mathforum.org