Vibrating string: Difference between revisions

From formulasearchengine
Jump to navigation Jump to search
en>Monkbot
 
Line 1: Line 1:
{{Even polygon db|Even polygon stat table|p30}}
Greetings. The writer's title is Phebe and she feels comfy when people use the full name. Since she was 18 she's been working as a receptionist but her marketing by no means comes. South Dakota is where me and my husband live. Body building is what my family members and I appreciate.<br><br>Here is my blog ... [http://www.missdica.com/a_gallery/1866456 at home std testing]
In [[geometry]], an '''triacontagon''' is a thirty-sided [[polygon]]. The sum of any triacontagon's interior angles is 5040 degrees.
 
One interior angle in a [[regular polygon|regular]] triacontagon is 168°, meaning that one exterior angle would be 12°. The triacontagon is the largest regular polygon whose interior angle is the sum of the interior angles of smaller polygons: 168° is the sum of the interior angles of the [[equilateral triangle]] (60°) and the [[regular pentagon]] (108°).
 
The regular triacontagon is a [[constructible polygon]], by an edge-[[bisection]] of a regular [[pentadecagon]], and can be seen as a [[Truncation (geometry)|truncated]] pentadecagon.
 
==Area==
The [[area]] of a regular triacontangon is (with {{nowrap|''t'' {{=}} edge length}})
:<math>A = \frac{15}{2} t^2 \cot \frac{\pi}{30}</math>
 
===Petrie polygons===
The regular triacontagon is the [[Petrie polygon]] for a number of higher dimensional polytopes with E<sub>8</sub> symmetry, shown in [[orthogonal projection]]s in the E<sub>8</sub> [[Coxeter plane]]:
 
{| class=wikitable
|- align=center valign=top
|[[File:4_21_t0_E8.svg|100px]]<BR>[[4 21 polytope|(4<sub>21</sub>)]]
|[[File:4_21_t1_E8.svg|100px]]<BR>[[Rectified 4 21 polytope|t<sub>1</sub>(4<sub>21</sub>)]]
|[[File:4_21_t2_E8.svg|100px]]<BR>t<sub>2</sub>(4<sub>21</sub>)
<!--|[[File:4_21_t3_E8.svg|100px]]<BR>t<sub>3</sub>(4<sub>21</sub>)-->
<!--|[[File:4_21_t4_E8.svg|100px]]<BR>t<sub>4</sub>(4<sub>21</sub>)-->
|[[File:2_41_t0_E8.svg|100px]]<BR>[[2_41 polytope|(2<sub>41</sub>)]]
|[[File:2_41_t1_E8.svg|100px]]<BR>[[Rectified 2_41 polytope|t<sub>1</sub>(2<sub>41</sub>)]]
<!--|[[File:1_42_t0_E8.svg|100px]]<BR>[[2_41 polytope|(1<sub>42</sub>)]]-->
|}
 
It is also the Petrie polygon for some higher dimensional polytopes with H<sub>4</sub> symmetry, shown in [[orthogonal projection]]s in the H<sub>4</sub> [[Coxeter plane]]:
 
{| class=wikitable
|- align=center valign=top
|[[File:120-cell graph H4.svg|100px]]<BR>[[120-cell]]
|[[File:120-cell_t1_H4.svg|100px]]<BR>[[Rectified 120-cell]]
|[[File:600-cell_t1_H4.svg|100px]]<BR>[[Rectified 600-cell]]
|[[File:600-cell graph H4.svg|100px]]<BR>[[600-cell]]
|}
 
==References==
{{Reflist}}
*{{MathWorld|title=Triacontagon|urlname=Triacontagon}}
*[http://mathforum.org/dr.math/faq/faq.polygon.names.html Naming Polygons and Polyhedra]
 
{{Clear}}
{{polygons}}
 
[[Category:Polygons]]
 
{{Elementary-geometry-stub}}

Latest revision as of 20:49, 3 January 2015

Greetings. The writer's title is Phebe and she feels comfy when people use the full name. Since she was 18 she's been working as a receptionist but her marketing by no means comes. South Dakota is where me and my husband live. Body building is what my family members and I appreciate.

Here is my blog ... at home std testing