{"id":431,"date":"2019-06-27T17:44:52","date_gmt":"2019-06-27T17:44:52","guid":{"rendered":"http:\/\/funfacts.104.42.120.246.xip.io\/?page_id=431"},"modified":"2019-12-09T22:18:26","modified_gmt":"2019-12-09T22:18:26","slug":"one-two-three-pi","status":"publish","type":"page","link":"https:\/\/math.hmc.edu\/funfacts\/one-two-three-pi\/","title":{"rendered":"One, Two, Three, Pi"},"content":{"rendered":"\n<div class=\"wp-block-image\"><figure class=\"alignright\"><img loading=\"lazy\" decoding=\"async\" width=\"100\" height=\"140\" data-attachment-id=\"1554\" data-permalink=\"https:\/\/math.hmc.edu\/funfacts\/one-two-three-pi\/20005-2-1\/\" data-orig-file=\"https:\/\/math.hmc.edu\/funfacts\/wp-content\/uploads\/sites\/4\/2019\/12\/20005.2.1.gif\" data-orig-size=\"100,140\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;0&quot;}\" data-image-title=\"20005.2.1\" data-image-description=\"\" data-image-caption=\"\" data-large-file=\"https:\/\/math.hmc.edu\/funfacts\/wp-content\/uploads\/sites\/4\/2019\/12\/20005.2.1.gif\" src=\"https:\/\/math.hmc.edu\/funfacts\/wp-content\/uploads\/sites\/4\/2019\/12\/20005.2.1.gif\" alt=\"\" class=\"wp-image-1554\"\/><\/figure><\/div>\n\n\n\n<p>Here&#8217;s an interesting formula:<\/p>\n\n\n\n<p style=\"text-align:center\">Arctan(1) + Arctan(2) + Arctan(3) = Pi.<\/p>\n\n\n\n<p>(Everything&#8217;s in radians, of course). <\/p>\n\n\n\n<p><strong>Presentation&nbsp;Suggestions:<\/strong><br>Challenge students to prove this fact.<\/p>\n\n\n\n<p><strong>The\u00a0Math\u00a0Behind\u00a0the\u00a0Fact:<\/strong><br>The Figure contains a hint; check that the angles of the three\u00a0triangles\u00a0at their common vertex add to Pi. Can you find a similar proof for the following equation?<br>Arctan(1\/2)+Arctan(1\/3) = Pi\/4.<\/p>\n\n\n\n<p><strong>How to Cite this Page:<\/strong>&nbsp;<br>Su, Francis E., et al. &#8220;One, Two, Three, Pi.&#8221;&nbsp;<em>Math Fun Facts<\/em>. &lt;http:\/\/www.math.hmc.edu\/funfacts&gt;.<\/p>\n\n\n\n<p><strong>References:<\/strong><br>R. Nelsen, <em><a href=\"https:\/\/www.amazon.com\/exec\/obidos\/ASIN\/0883857006\/ref=nosim\/mathfunfacts-20\">Proofs without Words<\/a><\/em>. p.39. <br>R. Vakil, <em><a href=\"https:\/\/www.amazon.com\/exec\/obidos\/ASIN\/1895997046\/ref=nosim\/mathfunfacts-20\">A Mathematical Mosaic<\/a><\/em>, 1996. p.86.<\/p>\n\n\n\n<p><strong>Fun Fact suggested by:   <\/strong><br>Stan Wagon<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Here&#8217;s an interesting formula: Arctan(1) + Arctan(2) + Arctan(3) = Pi. (Everything&#8217;s in radians, of course). Presentation&nbsp;Suggestions:Challenge students to prove&#46;&#46;&#46;<\/p>\n","protected":false},"author":7,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"tags":[8,4,144],"class_list":["post-431","page","type-page","status-publish","hentry","tag-geometry","tag-medium","tag-trigonometry"],"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/math.hmc.edu\/funfacts\/wp-json\/wp\/v2\/pages\/431","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/math.hmc.edu\/funfacts\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/math.hmc.edu\/funfacts\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/math.hmc.edu\/funfacts\/wp-json\/wp\/v2\/users\/7"}],"replies":[{"embeddable":true,"href":"https:\/\/math.hmc.edu\/funfacts\/wp-json\/wp\/v2\/comments?post=431"}],"version-history":[{"count":4,"href":"https:\/\/math.hmc.edu\/funfacts\/wp-json\/wp\/v2\/pages\/431\/revisions"}],"predecessor-version":[{"id":1555,"href":"https:\/\/math.hmc.edu\/funfacts\/wp-json\/wp\/v2\/pages\/431\/revisions\/1555"}],"wp:attachment":[{"href":"https:\/\/math.hmc.edu\/funfacts\/wp-json\/wp\/v2\/media?parent=431"}],"wp:term":[{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/math.hmc.edu\/funfacts\/wp-json\/wp\/v2\/tags?post=431"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}