Image talk:Neper's Circle.png
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I don't understand this diagram and I suspect it is incorrect. Spherical trigonometry states: Write the six angles of the triangle in the form of a circle, sticking to the order as they appear in the triangle (i.e.: start with a corner angle, write the arc angle of an attached side next to it, proceed with the next corner angle, etc. and close the circle). Then cross out the 90° corner angle and replace the arc angles adjacent to it by their complement to 90° (i.e. replace, say, a by 90° - a).
That means the angle to be removed is C, and the two arc angles to be replaced with their complements are a and b. The circle in the diagram does not show this. -- Tarquin 17:14, 8 May 2005 (UTC)
- You are right, the diagram is wrong. It seems to be the result of the superposition of two mistakes: Aparently, the source for this diagram was the External Link Intro to Spherical Trig. When it was copied into the page, the small c became a capital C. Also, the original diagram illustrates a different (but equivalent) version of Napier's rule, where the complement is taken of all angles except a and b, and instead of cotangents one has tangents, and sines instead of cosines and vice versa. I'm for correcting the figure and leaving the rule as it is, for this is the better known version. BSpringborn 16:15, 13 September 2005 (UTC)
I would also like to suggest removing the External Link Intro to Spherical Trig. In my opinion, the references to Buckminster-Fuller's book Synergetics constitute a non-neutral point of view. This is not compensated by valuable content. BSpringborn 16:15, 13 September 2005 (UTC)
- I have corrected the image. -- Eroica 08:33, 1 November 2005 (UTC)
I think this image should be remade using vector graphics. Smithers888 14:32, 23 November 2006 (UTC)
Also why is it called Neper's Circle instead of Napier's Circle. Smithers888 14:35, 23 November 2006 (UTC)
