{"id":377,"date":"2019-01-08T11:42:59","date_gmt":"2019-01-08T02:42:59","guid":{"rendered":"http:\/\/pobimath.synology.me\/wordpress\/?p=377"},"modified":"2019-01-08T11:53:40","modified_gmt":"2019-01-08T02:53:40","slug":"1%ea%b6%8c_%eb%aa%85%ec%a0%9c-13","status":"publish","type":"post","link":"http:\/\/pobimath.synology.me\/wordpress\/archives\/377","title":{"rendered":"1\uad8c_\uba85\uc81c 13"},"content":{"rendered":"<blockquote><p><b><a href=\"http:\/\/aleph0.clarku.edu\/~djoyce\/java\/elements\/bookI\/propI13.html\">Proposition 13.<\/a><\/b><\/p>\n<p>If a straight line stands on a straight line, then it makes either two right angles or angles whose sum equals two right angles.<\/p>\n<p>\ub450 \uc9c1\uc120\uc774 \ub9cc\ub098\uba74 \uc774\uc9c1\uac01(180\ub3c4)\uc744 \uc774\ub8e8\uac70\ub098 \ub450 \uac01\uc758 \ud569\uc774 \uc774\uc9c1\uac01\uc744 \uc774\ub8ec\ub2e4.<\/p><\/blockquote>\n<p>\uc9c1\uc120 $AB$\uc640 $CD$\uac00 \ub450 \uac01 $\\angle CBA$\uc640 $\\angle ABD$\ub97c \ub9cc\ub4e0\ub2e4\uace0 \ud558\uc790.<\/p>\n<p>\ub450 \uac01\uc758 \ud569\uc774 2\uc9c1\uac01\uc784\uc744 \ubcf4\uc774\ub824\uace0 \ud55c\ub2e4.<\/p>\n<p>\ub9cc\uc57d \ub450 \uac01\uc774 \ubaa8\ub450 \uc9c1\uac01\uc774\ub77c\uba74 \uc99d\uba85\uc774 \ub05d\ub09c\ub2e4.<\/p>\n<p>\ub450 \uac01\uc774 \uc9c1\uac01\uc774 \uc544\ub2c8\ub77c\uba74 \uc810 $B$\uc5d0\uc11c \uc9c1\uc120 $CD$\uc5d0 \uc218\uc120 $BE$\ub97c \uc791\ub3c4\ud560 \uc218 \uc788\ub2e4.<img loading=\"lazy\" class=\"aligncenter size-medium wp-image-379\" src=\"http:\/\/pobimath.synology.me\/wordpress\/wp-content\/uploads\/2019\/01\/proposition_13-300x231.png\" alt=\"\" width=\"300\" height=\"231\" srcset=\"http:\/\/pobimath.synology.me\/wordpress\/wp-content\/uploads\/2019\/01\/proposition_13-300x231.png 300w, http:\/\/pobimath.synology.me\/wordpress\/wp-content\/uploads\/2019\/01\/proposition_13.png 311w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/>\ub450 \uac01 $\\angle CBE$\uc640 $\\angle EBD$\uc758 \ud569\uc740 2\uc9c1\uac01\uc774\ub2e4.<\/p>\n<p>$$\\angle CBE =\\angle CBA +\\angle ABE$$<\/p>\n<p>\uc774\ubbc0\ub85c \uac01\uac01 $\\angle EBD$\ub97c \ub354\ud558\uba74<\/p>\n<p>$$\\angle CBE+\\angle EBD =\\angle CBA +\\angle ABE+\\angle EBD$$<\/p>\n<p>\uc138 \uac01 $\\angle CBA$, $\\angle ABE$, $\\angle EBD$\uc758 \ud569\uc740 2\uc9c1\uac01\uc774\ub2e4.<\/p>\n<p>\ub9c8\ucc2c\uac00\uc9c0\ub85c<\/p>\n<p>$$\\angle\u00a0DBA =\\angle\u00a0DBE +\\angle ABE$$<\/p>\n<p>\uc774\ubbc0\ub85c \uac01\uac01 $\\angle ABC$\ub97c \ub354\ud558\uba74<\/p>\n<p>$$\\angle\u00a0DBA +\\angle ABC=\\angle\u00a0DBE +\\angle ABE+\\angle ABC$$<\/p>\n<p>\uc704\uc5d0\uc11c \uc138 \uac01\uc744 \ub354\ud558\uba74 2\uc9c1\uac01\uc784\uc744 \ubcf4\uc600\uc73c\ubbc0\ub85c<\/p>\n<p>\ub450 \uac01\u00a0$\\angle\u00a0DBA$, $\\angle ABC$\uc744 \ub354\ud558\uba74 2\uc9c1\uac01\uc774\ub2e4.<\/p>\n<p style=\"text-align: right;\">$\\blacksquare$<\/p>\n<p>\uc5b4\uca4c\uba74 \ub2f9\uc5f0\ud55c \uac83\uc744 \uc5b4\ub835\uac8c \uc99d\uba85\ud558\uace0 \uc788\ub294 \uac83\ucc98\ub7fc \ubcf4\uc778\ub2e4. \uc55e\uc5d0\uc11c \uc774\uc57c\uae30\ud55c\ub300\ub85c \uc720\ud074\ub9ac\ub4dc\ub294 \uc9c1\uac01\uc740 \uc815\uc758\ud588\uc9c0\ub9cc \uc624\ub298\ub0a0 \uc4f0\ub294 60\ubd84\ubc95\uc73c\ub85c ${}^{\\circ}$\ub97c \uc815\uc758\ud558\uc9c0 \uc54a\uc558\ub2e4.\u00a0 \uc815\uc758\ud558\uc9c0 \ud558\uac70\ub098 \uacf5\ub9ac\ub85c\u00a0 \uc138\uc6b0\uc9c0 \uc54a\uc740 \uac83\uc740 \uc4f8 \uc218\uac00 \uc5c6\ub2e4.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Proposition 13. If a straight line stands on a straight line, then it makes either two right angles or angles whose sum equals two right angles. \ub450 \uc9c1\uc120\uc774 \ub9cc\ub098\uba74 \uc774\uc9c1\uac01(180\ub3c4)\uc744 \uc774\ub8e8\uac70\ub098 \ub450 \uac01\uc758 \ud569\uc774 \uc774\uc9c1\uac01\uc744 \uc774\ub8ec\ub2e4. \uc9c1\uc120 $AB$\uc640 $CD$\uac00 \ub450 \uac01 $\\angle CBA$\uc640 $\\angle ABD$\ub97c \ub9cc\ub4e0\ub2e4\uace0 \ud558\uc790. \ub450 \uac01\uc758 \ud569\uc774 2\uc9c1\uac01\uc784\uc744 \ubcf4\uc774\ub824\uace0 \ud55c\ub2e4. \ub9cc\uc57d \ub450 &hellip; <\/p>\n<p class=\"link-more\"><a href=\"http:\/\/pobimath.synology.me\/wordpress\/archives\/377\" class=\"more-link\">\ub354 \ubcf4\uae30<span class=\"screen-reader-text\"> &#8220;1\uad8c_\uba85\uc81c 13&#8221;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[4],"tags":[],"_links":{"self":[{"href":"http:\/\/pobimath.synology.me\/wordpress\/wp-json\/wp\/v2\/posts\/377"}],"collection":[{"href":"http:\/\/pobimath.synology.me\/wordpress\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/pobimath.synology.me\/wordpress\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/pobimath.synology.me\/wordpress\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/pobimath.synology.me\/wordpress\/wp-json\/wp\/v2\/comments?post=377"}],"version-history":[{"count":4,"href":"http:\/\/pobimath.synology.me\/wordpress\/wp-json\/wp\/v2\/posts\/377\/revisions"}],"predecessor-version":[{"id":400,"href":"http:\/\/pobimath.synology.me\/wordpress\/wp-json\/wp\/v2\/posts\/377\/revisions\/400"}],"wp:attachment":[{"href":"http:\/\/pobimath.synology.me\/wordpress\/wp-json\/wp\/v2\/media?parent=377"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/pobimath.synology.me\/wordpress\/wp-json\/wp\/v2\/categories?post=377"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/pobimath.synology.me\/wordpress\/wp-json\/wp\/v2\/tags?post=377"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}