Talk:Regular polygon

message: I have reverted the table to this version for the following reasons:
# The general formula should come first. Ssgxnh moved it back to the bottom. I'd like to insist having first.
# The reason for the empty cells is WP:UNSOURCED: is it true that "For these polygons the exact area does not simplify out of trig functions"? Perhaps some do simplify, but we just don't know. One of the non-empty cells had the marker as well. I.m.o. an empty cell is really ok. We don't have to put reasons for being empty in there.
# There is no reason why we should fear the cot-function and replace it with cos/sin. The latter formula does not belong in the approximated values column, not even with parenteses.
Ssgxnh, please propose and discuss on talk page before you make further changes? - Thanks - DVdm (talk) 21:12, 4 August 2010 (UTC)
replies: text: . That's a good idea. I have expanded the table with 3 colums for r=1 and ditto for a=1. The calculations are straightforward and were calculated with Maple 13. I guess we can assume that we have a consensus that this conforms to the spirit of wp:CALC. In any case, I have added a reference to the defined MAPLE function. DVdm (talk) 17:00, 4 November 2011 (UTC)

text: Some of the exact values are either unknown, or perhaps not expressable in radical form. - DVdm (talk) 15:28, 15 May 2018 (UTC)
thread_title:  Area table 

message: The measure of an interior angle of a regular n-gon is an integer number of degrees if and only if n divides 360. There are only 22 such n, namely, 3, 4, 5, 6, 8, 9, 10, 12, 15, 18, 20, 24, 30, 36, 40, 45, 60, 72, 90, 120, 180, and 360. For those values of n, the measures of the interior angles are 60°, 90°, 108°, 120°, 135°, 140°, 144°, 150°, 156°, 160°, 162°, 165°, 168°, 170°, 171°, 172°, 174°, 175°, 176°, 177°, 178°, and 179° respectively. GeoffreyT2000 (talk) 16:35, 18 April 2015 (UTC)
thread_title:  Interior angles 

message: Substituted at 02:33, 5 May 2016 (UTC)
thread_title: Assessment comment

message: I added \tfrac{p^2}{4n} \cot{\tfrac{\pi}{n}} as it was the form I was looking for when I loaded the page (and none of the others are in terms of just p,n). Is general policy to avoid any redundant formulae? If so I'm not sure why nsa/2 is there as it's also clearly pa/2.  Indivicivet (talk) 17:21, 10 December 2016 (UTC)
replies: text: There are literally thousands of ways these formulas can be written, so one needs to make some choices as to which ones should be given. The formula  is present because it is the clearest link to the area of a triangle form and so, the most basic version. Using  gives the simplest form using the perimeter. Your addition was a second application of this and I did not see the need for it as it did not add anything novel to the string of formulae.--Bill Cherowitzo  (talk) 19:13, 10 December 2016 (UTC)
thread_title: Area formulae

message: I recently added a theorem proved in 2004 by Hwa Young Lee about origami constructible polygons (she also proved many other things in the paper; it's worth a read if you haven't). I'm not sure I formatted the citation correctly. Help would be appreciated! DancingGrumpyCattalk | (ze/zir or she/her) 16:22, 9 January 2022 (UTC)
thread_title:  Origami Constructibility