Comments on: Puzzle – area of polygon with known coordinates http://jd2718.wordpress.com/2008/05/05/puzzle-area-of-polygon-with-known-coordinates/ Education, Math, Teaching, New York, Bronx, Union, Language, Travel Mon, 16 Nov 2009 16:03:43 +0000 http://wordpress.com/ hourly 1 By: rOn {THETA} http://jd2718.wordpress.com/2008/05/05/puzzle-area-of-polygon-with-known-coordinates/#comment-39019 rOn {THETA} Thu, 21 Aug 2008 14:13:50 +0000 http://jd2718.wordpress.com/?p=844#comment-39019 1. find for the area by green's theorem or determinants 2. use pick's theorem 3. to find for the vertex, [...] 1. find for the area by green’s theorem or determinants
2. use pick’s theorem
3. to find for the vertex, [...]

]]> By: Walking Randomly » Carnival of Mathematics #33 - The rushed edition! http://jd2718.wordpress.com/2008/05/05/puzzle-area-of-polygon-with-known-coordinates/#comment-37633 Walking Randomly » Carnival of Mathematics #33 - The rushed edition! Fri, 16 May 2008 17:39:32 +0000 http://jd2718.wordpress.com/?p=844#comment-37633 [...] of jd2718 asks Can we find the area of a quadrilateral from just it’s co-ordinates?, with some interesting answers in the comments section. I reckon a nice Wolfram Demonstration could [...] [...] of jd2718 asks Can we find the area of a quadrilateral from just it’s co-ordinates?, with some interesting answers in the comments section. I reckon a nice Wolfram Demonstration could [...]

]]> By: dr rick http://jd2718.wordpress.com/2008/05/05/puzzle-area-of-polygon-with-known-coordinates/#comment-37478 dr rick Tue, 06 May 2008 18:40:27 +0000 http://jd2718.wordpress.com/?p=844#comment-37478 I hadn't seen the shoelace algorithm before. It's a nice little generalisation of the fact that the area of the parallelogram (0,0). (a,b). (c,d). (a+c, b+d) is determinant [a c \\ b d] (so triangles follow, and all other polygons follow that). Pick's Theorem is a truly splendid thing. I hadn’t seen the shoelace algorithm before. It’s a nice little generalisation of the fact that the area of the parallelogram (0,0). (a,b). (c,d). (a+c, b+d) is determinant [a c \\ b d] (so triangles follow, and all other polygons follow that).

Pick’s Theorem is a truly splendid thing.

]]> By: Brent http://jd2718.wordpress.com/2008/05/05/puzzle-area-of-polygon-with-known-coordinates/#comment-37458 Brent Mon, 05 May 2008 11:05:11 +0000 http://jd2718.wordpress.com/?p=844#comment-37458 There's also <a href="https://secure.wikimedia.org/wikipedia/en/wiki/Pick%27s_theorem" rel="nofollow">Pick's Theorem</a>. There’s also Pick’s Theorem.

]]> By: Efrique http://jd2718.wordpress.com/2008/05/05/puzzle-area-of-polygon-with-known-coordinates/#comment-37449 Efrique Mon, 05 May 2008 02:55:14 +0000 http://jd2718.wordpress.com/?p=844#comment-37449 Uh, unless I'm missing something, isn't this just the three step process, (i) "answer the triangle question", (ii) "w.l.o.g., assume one vertex of the polygon is at 0", and (iii) "do the completely obvious thing to use the first answer to solve the general problem", no? Uh, unless I’m missing something, isn’t this just the three step process, (i) “answer the triangle question”,
(ii) “w.l.o.g., assume one vertex of the polygon is at 0″, and
(iii) “do the completely obvious thing to use the first answer to solve the general problem”,
no?

]]> By: Jackie http://jd2718.wordpress.com/2008/05/05/puzzle-area-of-polygon-with-known-coordinates/#comment-37447 Jackie Mon, 05 May 2008 00:53:46 +0000 http://jd2718.wordpress.com/?p=844#comment-37447 Sounds like the <a href="http://staff.imsa.edu/math/journal/volume2/articles/Shoelace.pdf" rel="nofollow">shoelace algorithm</a>. Sounds like the shoelace algorithm.

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