{"id":2494,"date":"2015-12-01T11:28:06","date_gmt":"2015-12-01T10:28:06","guid":{"rendered":"http:\/\/agora.xtec.cat\/ieportalbatea\/?p=2494"},"modified":"2015-12-01T11:28:06","modified_gmt":"2015-12-01T10:28:06","slug":"mirallet-mirallet-per-que-mhas-fet-tan-petitet","status":"publish","type":"post","link":"https:\/\/agora.xtec.cat\/ieportalbatea\/inici\/mirallet-mirallet-per-que-mhas-fet-tan-petitet\/","title":{"rendered":"Mirallet, mirallet per qu\u00e8 m&#8217;has fet tan petitet?"},"content":{"rendered":"<p style=\"text-align: justify;\">Avui els alumnes de 3r d&#8217;ESO hem recordat el teorema de Tales amb un experiment. Una alumna ha pintat el contorn de la seva cara sobre un mirall i, per sorpresa de tots, el dibuix ha resultat molt m\u00e9s petit que la cara en realitat. Hem pogut deduir\u00a0que les dist\u00e0ncies observades sobre el mirall s\u00f3n la meitat de les dist\u00e0ncies sobre la imatge virtual. Donat que la dist\u00e0ncia entre la figura real i el mirall \u00e9s prou curta (com a m\u00e0xim la longitud del bra\u00e7 que ha fet el dibuix) l\u2019efecte de perspectiva \u00e9s irrellevant i les dimensions del dibuix s\u00f3n la meitat de les dimensions de la cara real. Es tracta d\u2019un exemple de semblan\u00e7a amb ra\u00f3 1:2. Per\u00f2 el que sorpr\u00e8n m\u00e9s \u00e9s la superf\u00edcie que limita el contorn i que \u00e9s una quarta part de la superf\u00edcie de la cara. Ha estat una bona oportunitat per repassar el fet que la ra\u00f3 entre \u00e0rees de figures semblants \u00e9s igual al quadrat de la ra\u00f3 de semblan\u00e7a.<\/p>\n<div id='gallery-1' class='gallery galleryid-2494 gallery-columns-2 gallery-size-full'><figure class='gallery-item'>\n\t\t\t<div class='gallery-icon landscape'>\n\t\t\t\t<a href='https:\/\/agora.xtec.cat\/ieportalbatea\/inici\/mirallet-mirallet-per-que-mhas-fet-tan-petitet\/attachment\/f30_mirallet_mirallet\/'><img loading=\"lazy\" decoding=\"async\" width=\"400\" height=\"234\" src=\"https:\/\/agora.xtec.cat\/ieportalbatea\/wp-content\/uploads\/usu92\/2015\/12\/f30_mirallet_mirallet.jpg\" class=\"attachment-full size-full\" alt=\"\" srcset=\"https:\/\/agora.xtec.cat\/ieportalbatea\/wp-content\/uploads\/usu92\/2015\/12\/f30_mirallet_mirallet.jpg 400w, https:\/\/agora.xtec.cat\/ieportalbatea\/wp-content\/uploads\/usu92\/2015\/12\/f30_mirallet_mirallet-300x176.jpg 300w\" sizes=\"auto, (max-width: 400px) 100vw, 400px\" \/><\/a>\n\t\t\t<\/div><\/figure><figure class='gallery-item'>\n\t\t\t<div class='gallery-icon portrait'>\n\t\t\t\t<a href='https:\/\/agora.xtec.cat\/ieportalbatea\/inici\/mirallet-mirallet-per-que-mhas-fet-tan-petitet\/attachment\/mirallet2\/'><img loading=\"lazy\" decoding=\"async\" width=\"1984\" height=\"2646\" src=\"https:\/\/agora.xtec.cat\/ieportalbatea\/wp-content\/uploads\/usu92\/2015\/12\/mirallet2.jpg\" class=\"attachment-full size-full\" alt=\"\" srcset=\"https:\/\/agora.xtec.cat\/ieportalbatea\/wp-content\/uploads\/usu92\/2015\/12\/mirallet2.jpg 1984w, https:\/\/agora.xtec.cat\/ieportalbatea\/wp-content\/uploads\/usu92\/2015\/12\/mirallet2-225x300.jpg 225w, https:\/\/agora.xtec.cat\/ieportalbatea\/wp-content\/uploads\/usu92\/2015\/12\/mirallet2-768x1024.jpg 768w\" sizes=\"auto, (max-width: 1984px) 100vw, 1984px\" \/><\/a>\n\t\t\t<\/div><\/figure><figure class='gallery-item'>\n\t\t\t<div class='gallery-icon portrait'>\n\t\t\t\t<a href='https:\/\/agora.xtec.cat\/ieportalbatea\/inici\/mirallet-mirallet-per-que-mhas-fet-tan-petitet\/attachment\/mirallet3\/'><img loading=\"lazy\" decoding=\"async\" width=\"1984\" height=\"2646\" src=\"https:\/\/agora.xtec.cat\/ieportalbatea\/wp-content\/uploads\/usu92\/2015\/12\/mirallet3.jpg\" class=\"attachment-full size-full\" alt=\"\" srcset=\"https:\/\/agora.xtec.cat\/ieportalbatea\/wp-content\/uploads\/usu92\/2015\/12\/mirallet3.jpg 1984w, https:\/\/agora.xtec.cat\/ieportalbatea\/wp-content\/uploads\/usu92\/2015\/12\/mirallet3-225x300.jpg 225w, https:\/\/agora.xtec.cat\/ieportalbatea\/wp-content\/uploads\/usu92\/2015\/12\/mirallet3-768x1024.jpg 768w\" sizes=\"auto, (max-width: 1984px) 100vw, 1984px\" \/><\/a>\n\t\t\t<\/div><\/figure>\n\t\t<\/div>\n\n","protected":false},"excerpt":{"rendered":"<p>Avui els alumnes de 3r d&#8217;ESO hem recordat el teorema de Tales amb un experiment. Una alumna ha pintat el contorn de la seva cara sobre un mirall i, per sorpresa de tots, el dibuix ha resultat molt m\u00e9s petit que la cara en realitat. Hem pogut deduir\u00a0que les dist\u00e0ncies observades sobre el mirall s\u00f3n [&hellip;]<\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_bbp_topic_count":0,"_bbp_reply_count":0,"_bbp_total_topic_count":0,"_bbp_total_reply_count":0,"_bbp_voice_count":0,"_bbp_anonymous_reply_count":0,"_bbp_topic_count_hidden":0,"_bbp_reply_count_hidden":0,"_bbp_forum_subforum_count":0,"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[4],"tags":[26,77],"class_list":["post-2494","post","type-post","status-publish","format-standard","hentry","category-inici","tag-batea","tag-matematiques"],"post_mailing_queue_ids":[],"_links":{"self":[{"href":"https:\/\/agora.xtec.cat\/ieportalbatea\/wp-json\/wp\/v2\/posts\/2494","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/agora.xtec.cat\/ieportalbatea\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/agora.xtec.cat\/ieportalbatea\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/agora.xtec.cat\/ieportalbatea\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/agora.xtec.cat\/ieportalbatea\/wp-json\/wp\/v2\/comments?post=2494"}],"version-history":[{"count":3,"href":"https:\/\/agora.xtec.cat\/ieportalbatea\/wp-json\/wp\/v2\/posts\/2494\/revisions"}],"predecessor-version":[{"id":2501,"href":"https:\/\/agora.xtec.cat\/ieportalbatea\/wp-json\/wp\/v2\/posts\/2494\/revisions\/2501"}],"wp:attachment":[{"href":"https:\/\/agora.xtec.cat\/ieportalbatea\/wp-json\/wp\/v2\/media?parent=2494"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/agora.xtec.cat\/ieportalbatea\/wp-json\/wp\/v2\/categories?post=2494"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/agora.xtec.cat\/ieportalbatea\/wp-json\/wp\/v2\/tags?post=2494"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}