{"id":1093,"date":"2020-06-30T16:47:14","date_gmt":"2020-06-30T14:47:14","guid":{"rendered":"http:\/\/trabucaire.free.fr\/?p=1093"},"modified":"2026-08-21T17:27:22","modified_gmt":"2026-08-21T15:27:22","slug":"ii-effets-de-perspective","status":"publish","type":"post","link":"https:\/\/trabucaire.pages-perso.free.fr\/index.php\/maths-pour-se-divertir\/ii-effets-de-perspective\/","title":{"rendered":"II\u00b0\/ Effets de Perspective :"},"content":{"rendered":"<p><script type=\"text\/javascript\" src=\"https:\/\/cdn.geogebra.org\/apps\/deployggb.js\"><span data-mce-type=\"bookmark\" style=\"display: inline-block; width: 0px; overflow: hidden; line-height: 0;\" class=\"mce_SELRES_start\">\ufeff<\/span><span data-mce-type=\"bookmark\" style=\"display: inline-block; width: 0px; overflow: hidden; line-height: 0;\" class=\"mce_SELRES_start\">\ufeff<\/span><\/script><script type=\"text\/javascript\"> var applet1 = new GGBApplet({filename: \"\/Media\/geogebra\/Fichiers ggb\/Illusion de Ponzo.ggb\",\"showtoolbar\":false,borderColor:\"#1d19e5\",\"showResetIcon\":true,\"enableShiftDragZoom\":false}, true); var applet2 = new GGBApplet({filename: \"\/Media\/geogebra\/Fichiers ggb\/Illusions - Rues.ggb\",\"showtoolbar\":false,borderColor:\"#1d19e5\",\"showResetIcon\":true,\"enableShiftDragZoom\":false}, true); var applet3 = new GGBApplet({filename: \"\/Media\/geogebra\/Fichiers ggb\/Illusion de Delboeuf.ggb\",\"showtoolbar\":false,borderColor:\"#1d19e5\",\"showResetIcon\":true,\"enableShiftDragZoom\":false}, true); var applet4 = new GGBApplet({filename: \"\/Media\/geogebra\/Fichiers ggb\/Illusion de Day.ggb\",\"showtoolbar\":false,borderColor:\"#1d19e5\",\"showResetIcon\":true,\"enableShiftDragZoom\":false}, true); window.onload = function() { applet1.inject('applet_container1'); applet2.inject('applet_container2'); applet3.inject('applet_container3'); applet4.inject('applet_container4'); }<\/script><\/p>\n<p>La pr\u00e9sence de traits sugg\u00e9rant la perspective entra\u00eene des illusions de grandeur.<\/p>\n<p>Ainsi une forme paraissant plus \u00e9loign\u00e9e qu&rsquo;une autre sera vue plus grande.<\/p>\n<p><strong> 1\u00b0\/ <span style=\"text-decoration: underline;\">Le parall\u00e9logramme de Sander :<\/span><\/strong><\/p>\n<p><strong><img decoding=\"async\" src=\"\/Media\/Maths\/1a.jpg\" border=\"0\" \/><\/strong> Compare les longueurs AB et BC.<\/p>\n<p><strong> 2\u00b0\/ <span style=\"text-decoration: underline;\">L&rsquo;illusion de Ponzo : <\/span><\/strong><\/p>\n<div id=\"applet_container1\" style=\"width: 980px; height: 640px; display: block;\"><\/div>\n<p><strong><br \/>\n3\u00b0\/<span style=\"text-decoration: underline;\"> Les tables de Shepard : <\/span><\/strong>elles sont en fait identiques &#8230;<\/p>\n<p><object data=\"\/Media\/Illusion\/SWF\/shepard.swf\" type=\"application\/x-shockwave-flash\" width=\"531\" height=\"399\" data-mce-fragment=\"1\"><\/object> Cliquez sur la fl\u00e8che recourb\u00e9e pour v\u00e9rifier.<\/p>\n<p><strong> 4\u00b0\/ <span style=\"text-decoration: underline;\">L\u2019illusion \u00e0 damier :<\/span><\/strong><\/p>\n<table style=\"width: 100%;\" border=\"0\" align=\"left\">\n<tbody>\n<tr>\n<td style=\"width: 37.926%;\"><object data=\"\/Media\/Illusion\/SWF\/traits.swf\" type=\"application\/x-shockwave-flash\" width=\"489\" height=\"489\" data-mce-fragment=\"1\"><\/object><\/td>\n<td style=\"width: 62.0015%;\">La perspective, cr\u00e9e par le damier, rend le trait vertical rouge plus long que le jaune.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<table style=\"width: 100%;\" border=\"0\" align=\"left\">\n<tbody>\n<tr>\n<td style=\"width: 28.1363%;\"><img loading=\"lazy\" decoding=\"async\" class=\"\" src=\"\/Media\/Maths\/3a.jpg\" width=\"327\" height=\"277\" border=\"0\" \/><\/td>\n<td style=\"width: 71.7912%;\">Le point bleu est plus proche du sommet sup\u00e9rieur du triangle ou plus proche de la base du triangle ? L&rsquo;illusion provient du fait que la surface rose situ\u00e9e sous le point est plus grande que celle situ\u00e9 au dessus.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><strong>5\u00b0\/ <\/strong><span style=\"text-decoration: underline;\"><strong>La chambre d\u2019Ames :<\/strong><\/span><\/p>\n<p>La chambre d&rsquo;Ames fut construite par l&rsquo;ophtalmologiste am\u00e9ricain Adelbert Ames Jr. en 1946.<\/p>\n<p>Il se basa, pour cette construction, sur un concept d&rsquo;Hermann von Helmholtz \u00e0 la fin du XIXe si\u00e8cle. Elle est le fruit de l&rsquo;association de deux illusions.<\/p>\n<p><img decoding=\"async\" src=\"\/Media\/Maths\/4a.jpg\" border=\"0\" \/><img decoding=\"async\" src=\"\/Media\/Maths\/5a.jpg\" border=\"0\" \/><\/p>\n<p>Bon en fait c&rsquo;est une pi\u00e8ce d&rsquo;illusion optique. Il n&rsquo;y a AUCUN montage !<\/p>\n<p>1\/ La pi\u00e8ce appara\u00eet cubique si elle est observ\u00e9e \u00e0 partir d&rsquo;un point sp\u00e9cial (la vision doit s&rsquo;effectuer avec un seul \u0153il, afin d&rsquo;\u00e9liminer l&rsquo;effet st\u00e9r\u00e9oscopique, en fait elle est trap\u00e9zo\u00efdale).<\/p>\n<p>2\/ Les personnes grandissent ou r\u00e9tr\u00e9cissent en passant d&rsquo;un angle \u00e0 l&rsquo;autre.<br \/>\n<iframe loading=\"lazy\" src=\"https:\/\/player.vimeo.com\/video\/429546842\" width=\"640\" height=\"400\" frameborder=\"0\" allowfullscreen=\"allowfullscreen\"><\/iframe><br \/>\nCet effet est parfois utilis\u00e9 au cin\u00e9ma comme effet sp\u00e9cia<a title=\"Effet sp\u00e9cial\" href=\"http:\/\/fr.wikipedia.org\/wiki\/Effet_sp%C3%A9cial\">l<\/a> pour repr\u00e9senter des personnages de tailles diff\u00e9rentes.<\/p>\n<p><strong> 6\u00b0\/ <\/strong><strong><span style=\"text-decoration: underline;\">La tour de Pise<\/span> :<\/strong> Quelle est la tour la plus pench\u00e9e ?<\/p>\n<table style=\"width: auto; border-style: solid; border-color: #000000;\" border=\"0\">\n<tbody>\n<tr>\n<td style=\"border-style: solid; border-color: #000000; width: 50%;\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter\" src=\"\/Media\/Maths\/6a.jpg\" alt=\"\" width=\"600\" height=\"399\" \/><\/td>\n<td style=\"border-style: solid; border-color: #000000; width: 50%;\">\n<p align=\"center\"><iframe loading=\"lazy\" title=\"vimeo-player\" src=\"\/\/player.vimeo.com\/video\/1101230855?title=0&amp;amp;byline=0\" width=\"640\" height=\"360\" frameborder=\"0\" allowfullscreen=\"allowfullscreen\"><\/iframe><\/p>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p style=\"text-align: left;\" align=\"center\"><strong>La r\u00e9ponse est \u00e9videmment : aucune ! Les deux images sont tout simplement identiques&#8230;<\/strong><\/p>\n<p style=\"text-align: left;\">Voici une illusion qui est aussi saisissante qu&rsquo;elle est simple. Les deux images de la tour pench\u00e9e de Pise sont identiques, pourtant on a l&rsquo;impression que la tour du c\u00f4t\u00e9 droit penche davantage, comme si elle \u00e9tait photographi\u00e9e d&rsquo;un angle diff\u00e9rent. La raison est que le syst\u00e8me visuel traite les deux images comme si elles faisaient partie d&rsquo;une seule et m\u00eame sc\u00e8ne.<br \/>\nNormalement, si deux tours adjacentes ont m\u00eame angle, leurs contours convergent \u00e0 cause de la perspective, et ceci est pris en consid\u00e9ration par le syst\u00e8me visuel. Ainsi une fois confront\u00e9 avec 2 tours dont les contours sont parall\u00e8les, le syst\u00e8me visuel suppose qu&rsquo;elles doivent diverger&#8230; et c&rsquo;est ce que nous voyons.<\/p>\n<p style=\"text-align: left;\">De m\u00eame avec cette photo d&rsquo;une rue, que l&rsquo;on a simplement dupliqu\u00e9e. Les trottoirs ne semblent pas parall\u00e8les.<\/p>\n<div id=\"applet_container2\" style=\"width: 980px; height: 640px; display: block;\"><\/div>\n<p><strong><br \/>\n7\u00b0\/ <span style=\"text-decoration: underline;\">La rue :<\/span><\/strong><\/p>\n<p><strong><img decoding=\"async\" src=\"\/Media\/Maths\/7a.jpg\" border=\"0\" \/><\/strong> Quel est le segment le plus long : [AB] ou [CD] ?<\/p>\n<p><strong> 8\u00b0\/ <span style=\"text-decoration: underline;\">La croix de A.Kitaoka :<\/span><\/strong><\/p>\n<p><img decoding=\"async\" src=\"\/Media\/Maths\/8a.jpg\" border=\"0\" \/><\/p>\n<p>La croix rouge et rose n\u2019est-elle pas un peu tordue ?<\/p>\n<p><strong> 9\u00b0\/ <span style=\"text-decoration: underline;\">Les montres :<\/span> <\/strong>Ils sont de m\u00eame taille !!<\/p>\n<p><img decoding=\"async\" src=\"\/Media\/Maths\/9a.jpg\" border=\"0\" \/><\/p>\n<p><strong> 10\u00b0\/ <span style=\"text-decoration: underline;\">L\u2019illusion de Biangio Pinna :<\/span><\/strong><\/p>\n<p><object data=\"\/Media\/Illusion\/SWF\/baingio_pinna.swf\" type=\"application\/x-shockwave-flash\" width=\"650\" height=\"488\" data-mce-fragment=\"1\"><\/object><\/p>\n<p><strong> 11\u00b0\/ <span style=\"text-decoration: underline;\">L\u2019illusion de Delboeuf :<\/span><\/strong><\/p>\n<table style=\"width: 100%; border-collapse: collapse; border-style: solid; border-color: #000000;\">\n<tbody>\n<tr>\n<td style=\"border-style: solid; border-color: #000000; width: 50%;\"><img decoding=\"async\" class=\"aligncenter\" src=\"\/Media\/Maths\/10a.jpg\" border=\"0\" \/><img decoding=\"async\" class=\"aligncenter\" src=\"\/Media\/Maths\/11a.jpg\" border=\"0\" \/><img decoding=\"async\" class=\"aligncenter\" src=\"\/Media\/Maths\/12a.jpg\" border=\"0\" \/><\/td>\n<td style=\"border-style: solid; border-color: #000000; width: 50%;\"><span style=\"font-size: 14pt;\"><img decoding=\"async\" class=\"aligncenter\" src=\"\/Media\/Maths\/Illusions new\/Delboeuf illusion.jpg\" alt=\"\" width=\"700\" \/><\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"border-style: solid; border-color: #000000; width: 50%;\"><span style=\"font-size: 14pt;\">L&rsquo;anneau ext\u00e9rieur de B est identique \u00e0 l&rsquo;anneau int\u00e9rieur de A, tandis que <\/span><span style=\"font-size: 14pt;\">l&rsquo;anneau int\u00e9rieur de B est identique \u00e0 l&rsquo;anneau central de C.<\/span><br \/>\n<span style=\"font-size: 14pt;\">Mais quand on met les deux anneaux de A autour de ce m\u00eame anneau central de C, <\/span><span style=\"font-size: 14pt;\">il ne manque plus qu&rsquo;un anneau pour avoir une figure faite de cercles concentriques \u00e9quidistants&#8230;<\/span><\/td>\n<td style=\"border-style: solid; border-color: #000000; width: 50%;\"><span style=\"font-size: 14pt;\">Dans quelle figure les parties roses sont-elles les plus grandes ?<\/span><\/p>\n<p><span style=\"font-size: 14pt;\">Bien entendu elles sont parfaitement identiques. Cependant notre cerveau interpr\u00e8te le dessus de l&rsquo;arc de cercle comme \u00e9tant plus \u00e9troit que le dessous.<br \/>\nLes parties roses en subissent les cons\u00e9quences et prennent plus ou moins d&rsquo;ampleur.<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>&nbsp;<\/p>\n<div id=\"applet_container3\" style=\"width: 980px; height: 640px; display: block;\"><\/div>\n<p><strong><br \/>\n12\u00b0\/ <span style=\"text-decoration: underline;\">L\u2019illusion de Day :<\/span><\/strong><\/p>\n<p><object data=\"\/Media\/Illusion\/SWF\/day.swf\" type=\"application\/x-shockwave-flash\" width=\"650\" height=\"488\" data-mce-fragment=\"1\"><\/object><\/p>\n<div id=\"applet_container4\" style=\"width: 980px; height: 640px; display: block;\"><\/div>\n<p><strong><br \/>\n13\u00b0\/ <span style=\"text-decoration: underline;\">Des photos \u00e9tonnantes :<\/span><\/strong><\/p>\n<table style=\"width: 100%; border-collapse: collapse; border-style: solid; border-color: #000000;\">\n<tbody>\n<tr>\n<td style=\"border-style: solid; border-color: #000000; width: 33.33%;\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter\" src=\"\/Media\/Maths\/IllusionsPerspective\/main-illusion.jpg\" width=\"500\" height=\"573\" border=\"0\" \/><\/td>\n<td style=\"border-style: solid; border-color: #000000; width: 33.33%;\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter\" src=\"\/Media\/Maths\/IllusionsPerspective\/visage-illusion.jpg\" width=\"500\" height=\"483\" border=\"0\" \/><\/td>\n<td style=\"border-style: solid; border-color: #000000; width: 33.33%;\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter\" src=\"\/Media\/Maths\/IllusionsPerspective\/Cycliste qui tombe.jpg\" width=\"500\" height=\"573\" border=\"0\" \/><\/td>\n<\/tr>\n<tr>\n<td style=\"border-style: solid; border-color: #000000; width: 33.33%; text-align: center;\"><strong>Je tiens entre mes 2 doigts<\/strong><\/td>\n<td style=\"border-style: solid; border-color: #000000; width: 33.33%; text-align: center;\"><strong>Cet homme est-il de face ou de profil ?<\/strong><\/td>\n<td style=\"border-style: solid; border-color: #000000; width: 33.33%; text-align: center;\"><strong>Tiens bon !!<\/strong><\/td>\n<\/tr>\n<tr>\n<td style=\"border-style: solid; border-color: #000000; width: 33.33%;\"><div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-27\" class=\"h5p-iframe\" data-content-id=\"27\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"Illusion - Madame chaise\"><\/iframe><\/div><\/td>\n<td style=\"border-style: solid; border-color: #000000; width: 33.33%;\"><iframe loading=\"lazy\" src=\"\/\/player.vimeo.com\/video\/717032848?title=0&amp;amp;byline=0\" width=\"640\" height=\"400\" frameborder=\"0\" allowfullscreen=\"allowfullscreen\"><\/iframe><\/td>\n<td style=\"border-style: solid; border-color: #000000; width: 33.33%;\"><strong><iframe loading=\"lazy\" src=\"\/\/player.vimeo.com\/video\/1216350540?title=0&amp;amp;byline=0\" width=\"425\" height=\"350\" allowfullscreen=\"allowfullscreen\"><\/iframe><\/strong><\/td>\n<\/tr>\n<tr>\n<td style=\"border-style: solid; border-color: #000000; width: 33.33%; text-align: center;\"><strong>Madame est bien petite assise sur sa chaise.<br \/>\nAh ben non !!!<\/strong><\/td>\n<td style=\"border-style: solid; border-color: #000000; width: 33.33%; text-align: center;\"><strong>La vitesse du train est toujours la m\u00eame, ce<br \/>\nqui\u00a0<\/strong><strong>change c&rsquo;est seulement le point de vue.<br \/>\nOn a l\u2019impression pourtant de ralentir.<\/strong><\/td>\n<td style=\"border-style: solid; border-color: #000000; width: 33.33%;\">\n<p style=\"text-align: left;\"><strong>Lorsque la plaque tourne, le parapluie se d\u00e9place dans un plan vertical.<\/strong><br \/>\n<strong><span style=\"font-family: inherit; font-size: inherit;\">Quelle forme prend le parapluie dans le plan ?<br \/>\n<\/span>\u00c9tonnamment, c\u2019est une hyperbole (avec la poign\u00e9e du parapluie incluse).<\/strong><\/p>\n<\/td>\n<\/tr>\n<tr>\n<td style=\"border-style: solid; border-color: #000000; width: 33.33%;\"><img decoding=\"async\" class=\"aligncenter\" src=\"\/Media\/Maths\/IllusionsPerspective\/Effet visuel - Chaise.gif\" alt=\"\" width=\"500\" \/><\/td>\n<td style=\"border-style: solid; border-color: #000000; width: 33.33%;\"><iframe loading=\"lazy\" src=\"\/\/player.vimeo.com\/video\/717032828?title=0&amp;amp;byline=0\" width=\"640\" height=\"400\" frameborder=\"0\" allowfullscreen=\"allowfullscreen\"><\/iframe><\/td>\n<td style=\"border-style: solid; border-color: #000000; width: 33.33%;\"><iframe loading=\"lazy\" src=\"\/\/player.vimeo.com\/video\/800883757?title=0&amp;amp;byline=0\" width=\"640\" height=\"400\" frameborder=\"0\" allowfullscreen=\"allowfullscreen\"><\/iframe><\/td>\n<\/tr>\n<tr>\n<td style=\"border-style: solid; border-color: #000000; width: 33.33%; text-align: center;\"><strong>C&rsquo;est quoi cette chaise ?<\/strong><\/td>\n<td style=\"border-style: solid; border-color: #000000; width: 33.33%; text-align: center;\"><strong>Comprenez vous ce jeu d&rsquo;ombre ?<\/strong><\/td>\n<td style=\"border-style: solid; border-color: #000000; width: 33.33%; text-align: center;\"><strong>Pauvre nez !!! Enfin regardez bien la fin de la vid\u00e9o.<\/strong><\/td>\n<\/tr>\n<tr>\n<td style=\"border-style: solid; border-color: #000000; width: 33.33%;\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter\" src=\"\/Media\/Maths\/Illusions new\/Perspective 02.jpg\" alt=\"\" width=\"500\" height=\"606\" \/><\/td>\n<td style=\"border-style: solid; border-color: #000000; width: 33.33%;\"><img decoding=\"async\" class=\"aligncenter\" src=\"\/Media\/Maths\/Illusions new\/Perspective 01.jpg\" alt=\"\" width=\"500\" \/><\/td>\n<td style=\"border-style: solid; border-color: #000000; width: 33.33%;\">\n<div style=\"padding: 120% 0 0 0; position: relative;\"><iframe loading=\"lazy\" style=\"position: absolute; top: 0; left: 0; width: 100%; height: 100%;\" title=\"How to draw a 3D ladder\" src=\"\/\/player.vimeo.com\/video\/1216367256?title=0&amp;amp;byline=0\" width=\"425\" height=\"350\" frameborder=\"0\"><\/iframe><\/div>\n<p><script src=\"https:\/\/player.vimeo.com\/api\/player.js\"><\/script><\/td>\n<\/tr>\n<tr>\n<td style=\"border-style: solid; border-color: #000000; width: 33.33%; text-align: center;\"><strong>Magnifique perspective.<\/strong><\/td>\n<td style=\"border-style: solid; border-color: #000000; width: 33.33%; text-align: center;\"><strong>Un Kal\u00e9idoscope, non un pyl\u00f4ne \u00e9lectrique.<\/strong><\/td>\n<td style=\"border-style: solid; border-color: #000000; width: 33.33%; text-align: center;\"><strong>Comment dessiner une \u00e9chelle virtuelle ?<\/strong><\/td>\n<\/tr>\n<tr>\n<td style=\"border-style: solid; border-color: #000000; width: 33.33%;\">\n<div style=\"padding: 100% 0 0 0; position: relative;\"><iframe loading=\"lazy\" style=\"position: absolute; top: 0; left: 0; width: 100%; height: 100%;\" title=\"Raisonnance\" src=\"\/\/player.vimeo.com\/video\/1216350541?title=0&amp;amp;byline=0\" width=\"425\" height=\"350\" frameborder=\"0\" data-mce-fragment=\"1\"><\/iframe><\/div>\n<p><strong><script src=\"https:\/\/player.vimeo.com\/api\/player.js\"><\/script><br \/>\n<\/strong><\/td>\n<td style=\"border-style: solid; border-color: #000000; width: 33.33%;\">\n<div style=\"padding: 120% 0 0 0; position: relative;\"><iframe loading=\"lazy\" style=\"position: absolute; top: 0; left: 0; width: 100%; height: 100%;\" title=\" Le blog-notes mathematique du coyote\" src=\"\/\/player.vimeo.com\/video\/1216367318?title=0&amp;amp;byline=0\" width=\"425\" height=\"350\" frameborder=\"0\"><\/iframe><\/div>\n<p><script src=\"https:\/\/player.vimeo.com\/api\/player.js\"><\/script><\/td>\n<td style=\"border-style: solid; border-color: #000000; width: 33.33%;\"><iframe loading=\"lazy\" src=\"\/\/player.vimeo.com\/video\/1216367255?title=0&amp;amp;byline=0\" width=\"640\" height=\"400\" frameborder=\"0\" allowfullscreen=\"allowfullscreen\"><\/iframe><\/td>\n<\/tr>\n<tr>\n<td style=\"border-style: solid; border-color: #000000; width: 33.33%; text-align: center;\"><strong>Visualisation de la <strong class=\"svelte-1fz0gqk\"><span class=\"svelte-1fz0gqk\">r\u00e9sonance<\/span><\/strong>.<\/strong><\/td>\n<td style=\"border-style: solid; border-color: #000000; width: 33.33%; text-align: center;\"><strong>Comment dessiner un cube 3D avec classe.<\/strong><\/td>\n<td style=\"border-style: solid; border-color: #000000; width: 33.33%; text-align: center;\">Chaise de Vivian Chiu<\/td>\n<\/tr>\n<tr>\n<td style=\"border-style: solid; border-color: #000000; width: 33.33%; text-align: center;\"><strong><iframe loading=\"lazy\" src=\"\/\/player.vimeo.com\/video\/1216367253?title=0&amp;amp;byline=0\" width=\"640\" height=\"400\" frameborder=\"0\" allowfullscreen=\"allowfullscreen\"><\/iframe><\/strong><\/td>\n<td style=\"border-style: solid; border-color: #000000; width: 33.33%; text-align: center;\"><strong>\u00a0<\/strong><\/td>\n<td style=\"border-style: solid; border-color: #000000; width: 33.33%; text-align: center;\"><\/td>\n<\/tr>\n<tr>\n<td style=\"border-style: solid; border-color: #000000; width: 33.33%; text-align: center;\"><strong>La plaque rectangulaire int\u00e9rieure tourne selon un axe diagonal. Le plan vertical repr\u00e9sente alors un octogone.<\/strong><\/td>\n<td style=\"border-style: solid; border-color: #000000; width: 33.33%; text-align: center;\"><strong>\u00a0<\/strong><\/td>\n<td style=\"border-style: solid; border-color: #000000; width: 33.33%; text-align: center;\"><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>La pr\u00e9sence de traits sugg\u00e9rant la perspective entra\u00eene des illusions de grandeur. Ainsi une forme paraissant plus \u00e9loign\u00e9e qu&rsquo;une autre sera vue plus grande. 1\u00b0\/ Le parall\u00e9logramme de Sander : Compare les longueurs AB et BC. 2\u00b0\/ L&rsquo;illusion de Ponzo : 3\u00b0\/ Les tables de Shepard : elles sont en fait identiques &#8230; Cliquez sur &#8230; <a title=\"II\u00b0\/ Effets de Perspective :\" class=\"read-more\" href=\"https:\/\/trabucaire.pages-perso.free.fr\/index.php\/maths-pour-se-divertir\/ii-effets-de-perspective\/\" aria-label=\"En savoir plus sur II\u00b0\/ Effets de Perspective :\">Lire la suite<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[27,6],"tags":[47,31],"class_list":["post-1093","post","type-post","status-publish","format-standard","hentry","category-les-illusions-doptiques","category-maths-pour-se-divertir","tag-illusions","tag-maths-pour-ce-divertir"],"_links":{"self":[{"href":"https:\/\/trabucaire.pages-perso.free.fr\/index.php\/wp-json\/wp\/v2\/posts\/1093","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/trabucaire.pages-perso.free.fr\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/trabucaire.pages-perso.free.fr\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/trabucaire.pages-perso.free.fr\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/trabucaire.pages-perso.free.fr\/index.php\/wp-json\/wp\/v2\/comments?post=1093"}],"version-history":[{"count":9,"href":"https:\/\/trabucaire.pages-perso.free.fr\/index.php\/wp-json\/wp\/v2\/posts\/1093\/revisions"}],"predecessor-version":[{"id":11474,"href":"https:\/\/trabucaire.pages-perso.free.fr\/index.php\/wp-json\/wp\/v2\/posts\/1093\/revisions\/11474"}],"wp:attachment":[{"href":"https:\/\/trabucaire.pages-perso.free.fr\/index.php\/wp-json\/wp\/v2\/media?parent=1093"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/trabucaire.pages-perso.free.fr\/index.php\/wp-json\/wp\/v2\/categories?post=1093"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/trabucaire.pages-perso.free.fr\/index.php\/wp-json\/wp\/v2\/tags?post=1093"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}