Wikipedia:Featured picture candidates/Construction of a regular pentagon

Construction of a regular pentagon
Voting period ends on 27 Oct 2010 at 21:51:40 (UTC)
 * Reason:Instructive animation that illustrates a mathematical concept
 * Articles in which this image appears:Pentagon, Prime number, Compass and straightedge constructions, Constructible polygon
 * FP category for this image:Diagrams,_drawings,_and_maps/Diagrams
 * Creator:TokyoJunkie


 * Support as nominator --Spikebrennan (talk) 21:51, 18 October 2010 (UTC)
 * Support fascinating.--TonyTheTiger (T/C/BIO/WP:CHICAGO/WP:FOUR) 23:47, 18 October 2010 (UTC)
 * Comment After the first two corners are identified, why not simply use the compass to determine the other points? --Elekhh (talk) 02:15, 19 October 2010 (UTC)
 * Comment Is the angle between the midpoint of the radius and the point on the vertical diameter of the circle arbitrary? Does the location of that line's endpoint matter? I consider myself to be decently educated in mathematics, but I can't follow this concept nor how the chord is established to form the 5 sides of the pentagon. Where does the chord (in bold) come from exactly? Maybe indicate its origin previously with a distinct color. -- mcshadypl T C  04:48, 19 October 2010 (UTC)
 * If I'm reading you correctly, it looks to me like it's the middle of the angle. Draw vertical diameter, then horizontal radius; draw line from midpoint of radius to top point of diameter; draw line bisecting that angle to diameter; draw line from that point parallel to radius; draw line from that resulting point to top of vertical diameter; voila, you have the first leg of a pentagon! --Golbez (talk) 15:20, 19 October 2010 (UTC)
 * And based on my analysis, I must support because this is neat and very informative. --Golbez (talk) 15:20, 19 October 2010 (UTC)
 * Oppose, sorry it's not clear enough for my little brain - the first "chapter" is ok (but does require quite a lot of attention), but then the subsequent steps are far too fast - you just have to assume that it's doing the same as the first, "spread out" bit. Would consider supporting if you slowed it down, or maybe even did the whole thing in full, not with the shortcuts. Aaadddaaammm (talk) 17:37, 19 October 2010 (UTC)
 * Comment: Can this be made larger?  Spencer T♦ C 21:46, 19 October 2010 (UTC)
 * As I understand it, animated GIF's are limited in in size for bandwidth. So if it was bigger then only the first frame would be shown in thumbnail view.--RDBury (talk) 11:28, 20 October 2010 (UTC)


 * Support - when i was at school tho i just drew a straight line and did 108 degree lines going off it, worked just as good without all the hassle lol --Thanks, Hadseys 21:48, 19 October 2010 (UTC)
 * Support awesome! Nergaal (talk) 05:10, 20 October 2010 (UTC)
 * Weak Oppose: While the animation does illustrate the construction well, though I don't think it's as visually striking as I would expect for an FP, there are a couple issues with the construction itself. First, once a side has been constructed, the remaining sides can be copied from it. But the animation clearly shows the entire construction being repeated, unnecessary and inelegant. Second, the source for the construction is MathWorld, and while that's often a good starting point when writing an article, it does have a reputation for including material that is unencyclopedic by Wikipedia standards. Constructions of a pentagon in a circle have been known since the the ancient Greeks, and while the article gives an additional secondary source, I think additional ones should be found to indicate that this particular construction is of encyclopedic value. Third, though perhaps a minor point, three steps used in the construction, the bisection of a line segment, the bisection of an angle, and the construction of a perpendicular to a line at a given point, actually require several steps to complete with a ruler and compass. So the actual construction is significantly more complex than the animation would suggest at first glance. The animation is encyclopedic but I would suggest that featured content should meet a higher standard than this does.--RDBury (talk) 13:08, 20 October 2010 (UTC)
 * Comment The whole point of the construction of a figure is that you can only use a straightedge and a pencil - no protractor. WiiWillieWiki —Preceding unsigned comment added by 158.158.223.2 (talk) 16:46, 20 October 2010 (UTC)
 * This construction is possible with a ruler and compass. Papa Lima Whiskey (talk) 23:10, 22 October 2010 (UTC)
 * That's what I meant. It was an objection who said that the pentagon should just be constructed from the first side, and then have a protractor to copy the angle. WiiWillieWiki —Preceding unsigned comment added by 158.158.240.230 (talk) 19:59, 26 October 2010 (UTC)
 * Oppose per RDBury. Papa Lima Whiskey (talk) 23:10, 22 October 2010 (UTC)

--Makeemlighter (talk) 00:42, 28 October 2010 (UTC)