{"action":"closed","issue":{"url":"https://api.github.com/repos/Khan/khan-exercises/issues/155982","labels_url":"https://api.github.com/repos/Khan/khan-exercises/issues/155982/labels{/name}","comments_url":"https://api.github.com/repos/Khan/khan-exercises/issues/155982/comments","events_url":"https://api.github.com/repos/Khan/khan-exercises/issues/155982/events","html_url":"https://github.com/Khan/khan-exercises/issues/155982","id":25056400,"number":155982,"title":"Basic triangle proofs - Why is angle DCE congruent to BAC.","user":{"login":"KhanBugz","id":924247,"avatar_url":"https://avatars.githubusercontent.com/u/924247?v=3","gravatar_id":"","url":"https://api.github.com/users/KhanBugz","html_url":"https://github.com/KhanBugz","followers_url":"https://api.github.com/users/KhanBugz/followers","following_url":"https://api.github.com/users/KhanBugz/following{/other_user}","gists_url":"https://api.github.com/users/KhanBugz/gists{/gist_id}","starred_url":"https://api.github.com/users/KhanBugz/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/KhanBugz/subscriptions","organizations_url":"https://api.github.com/users/KhanBugz/orgs","repos_url":"https://api.github.com/users/KhanBugz/repos","events_url":"https://api.github.com/users/KhanBugz/events{/privacy}","received_events_url":"https://api.github.com/users/KhanBugz/received_events","type":"User","site_admin":false},"labels":[{"url":"https://api.github.com/repos/Khan/khan-exercises/labels/chrome","name":"chrome","color":"e102d8"},{"url":"https://api.github.com/repos/Khan/khan-exercises/labels/scratchpad","name":"scratchpad","color":"DDDDDD"},{"url":"https://api.github.com/repos/Khan/khan-exercises/labels/vista","name":"vista","color":"ededed"},{"url":"https://api.github.com/repos/Khan/khan-exercises/labels/wrong-or-unclear","name":"wrong-or-unclear","color":"FFA500"}],"state":"closed","locked":false,"assignee":null,"milestone":null,"comments":0,"created_at":"2014-01-04T16:53:48Z","updated_at":"2015-11-18T00:04:49Z","closed_at":"2015-11-18T00:04:49Z","body":"Why is angle DCE congruent to BAC? I think this figure needs to be checked out an clarified. \n\n[geometry_proofs_intro.html?seed=28&problem=alternate](http://sandcastle.kasandbox.org/media/castles/Khan:master/exercises/geometry_proofs_intro.html?seed=28&problem=alternate&debug&lang=en)\n\n[Answer timeline](http://sandcastle.kasandbox.org/media/castles/Khan:master/exercises/geometry_proofs_intro.html?seed=28&problem=alternate&debug&lang=en&activity=%5B%5D)\n\n    []\n\nLocale: en\n\nUser hash: 1782074663\n\nMozilla/5.0 (Windows NT 6.0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/31.0.1650.63 Safari/537.36\n\nMathJax is loaded, ready, queue length: 0\n\n\n\nstart of log\nloadModule mod /khan-exercises/utils/answer-types.js\nloadModule mod /khan-exercises/utils/tmpl.js\nloadModule mod /khan-exercises/utils/tex.js\nloadModule mod /khan-exercises/utils/jquery.adhesion.js\nloadModule mod /khan-exercises/utils/calculator.js\nloadModule mod /khan-exercises/third_party/MathJax/2.1/MathJax.js?config=KAthJax-9e2776ffe7d2006f16f36d0d55d9464b\nloadScript loading /khan-exercises/third_party/MathJax/2.1/MathJax.js?config=KAthJax-9e2776ffe7d2006f16f36d0d55d9464b\nloadScript loaded /khan-exercises/third_party/MathJax/2.1/MathJax.js?config=KAthJax-9e2776ffe7d2006f16f36d0d55d9464b\nstartTask...\nstartTask got task undefined\nloadExercise start triangle_angles_1.html\nloadExercise start complementary_and_supplementary_angles.html\nloading and rendering geometry_proofs_intro\nloadExercise start geometry_proofs_intro.html\nloadExercise got triangle_angles_1.html\nloadExercise submod math\nloadModule mod /khan-exercises/utils/math.js\nloadModule mod /khan-exercises/utils/../third_party/raphael.js\nloadModule mod /khan-exercises/utils/knumber.js\nloadExercise submod graphie\nloadModule mod /khan-exercises/utils/graphie.js\nloadModule mod /khan-exercises/utils/kpoint.js\nloadModule mod /khan-exercises/utils/kvector.js\nloadExercise submod graphie-helpers\nloadModule mod /khan-exercises/utils/graphie-helpers.js\nloadModule mod /khan-exercises/utils/math-format.js\nloadModule mod /khan-exercises/utils/expressions.js\nloadExercise submod graphie-geometry\nloadModule mod /khan-exercises/utils/graphie-geometry.js\nloadModule mod /khan-exercises/utils/kmatrix.js\nloadModule mod /khan-exercises/utils/kline.js\nloadExercise submod math-format\nloadExercise submod answer-types\nloadExercise submod tmpl\nloadExercise submod tex\nloadExercise submod jquery.adhesion\nloadExercise submod calculator\nloadExercise submod /khan-exercises/third_party/MathJax/2.1/MathJax.js?config=KAthJax-9e2776ffe7d2006f16f36d0d55d9464b\nloadExercise finish triangle_angles_1.html\nloadExercise got geometry_proofs_intro.html\nloadExercise submod math\nloadExercise submod graphie\nloadExercise submod graphie-helpers\nloadExercise submod graphie-geometry\nloadExercise submod math-format\nloadExercise submod interactive\nloadModule mod /khan-exercises/utils/interactive.js\nloadModule mod /khan-exercises/utils/../third_party/jquery.mobile.vmouse.js\nloadExercise submod proofs\nloadModule mod /khan-exercises/utils/proofs.js\nloadExercise submod congruency\nloadModule mod /khan-exercises/utils/congruency.js\nloadModule mod /khan-exercises/utils/angles.js\nloadExercise submod answer-types\nloadExercise submod tmpl\nloadExercise submod tex\nloadExercise submod jquery.adhesion\nloadExercise submod calculator\nloadExercise submod /khan-exercises/third_party/MathJax/2.1/MathJax.js?config=KAthJax-9e2776ffe7d2006f16f36d0d55d9464b\nloadExercise finish geometry_proofs_intro.html\nloaded geometry_proofs_intro, now rendering\nloadModule mod /khan-exercises/utils/scratchpad.js\nstart of makeProblem\nchose problem type and seed for geometry_proofs_intro\ncloned problem\ncloned global elements\nran tmplApply to vars and main elements\nran tmplApply to [id]\nremoved hints from DOM\nevaled inline scripts\nadded inline styles\n(answer-typesLoad not a fn; src undefined)\nrunning tmplLoad\nran tmplLoad\n(texLoad not a fn; src undefined)\n(jquery.adhesionLoad not a fn; src undefined)\n(calculatorLoad not a fn; src undefined)\nrunning mathLoad\nran mathLoad\n(../third_party/raphaelLoad not a fn; src undefined)\n(knumberLoad not a fn; src undefined)\nrunning graphieLoad\nran graphieLoad\nrunning kpointLoad\nran kpointLoad\nrunning kvectorLoad\nran kvectorLoad\n(graphie-helpersLoad not a fn; src undefined)\n(math-formatLoad not a fn; src undefined)\n(expressionsLoad not a fn; src undefined)\nrunning graphie-geometryLoad\nran graphie-geometryLoad\n(kmatrixLoad not a fn; src undefined)\nrunning klineLoad\nran klineLoad\nrunning interactiveLoad\nran interactiveLoad\n(../third_party/jquery.mobile.vmouseLoad not a fn; src undefined)\n(proofsLoad not a fn; src undefined)\n(congruencyLoad not a fn; src undefined)\n(anglesLoad not a fn; src undefined)\ndone with runModules Load\n(answer-types not a fn; src undefined)\nrunning tmpl\nran tmpl\nrunning tex\nran tex\n(jquery.adhesion not a fn; src undefined)\n(calculator not a fn; src undefined)\n(math not a fn; src undefined)\n(../third_party/raphael not a fn; src undefined)\n(knumber not a fn; src undefined)\nrunning graphie\nran graphie\n(kpoint not a fn; src undefined)\n(kvector not a fn; src undefined)\n(graphie-helpers not a fn; src undefined)\n(math-format not a fn; src undefined)\n(expressions not a fn; src undefined)\n(graphie-geometry not a fn; src undefined)\n(kmatrix not a fn; src undefined)\n(kline not a fn; src undefined)\n(interactive not a fn; src undefined)\n(../third_party/jquery.mobile.vmouse not a fn; src undefined)\n(proofs not a fn; src undefined)\n(congruency not a fn; src undefined)\n(angles not a fn; src undefined)\ndone with runModules\ndecided on answer type custom\n(answer-types not a fn; src undefined)\nrunning tmpl\nran tmpl\nrunning tex\nran tex\n(jquery.adhesion not a fn; src undefined)\n(calculator not a fn; src undefined)\n(math not a fn; src undefined)\n(../third_party/raphael not a fn; src undefined)\n(knumber not a fn; src undefined)\nrunning graphie\nran graphie\n(kpoint not a fn; src undefined)\n(kvector not a fn; src undefined)\n(graphie-helpers not a fn; src undefined)\n(math-format not a fn; src undefined)\n(expressions not a fn; src undefined)\n(graphie-geometry not a fn; src undefined)\n(kmatrix not a fn; src undefined)\n(kline not a fn; src undefined)\n(interactive not a fn; src undefined)\n(../third_party/jquery.mobile.vmouse not a fn; src undefined)\n(proofs not a fn; src undefined)\n(congruency not a fn; src undefined)\n(angles not a fn; src undefined)\nvalidator created\nloadExercise got complementary_and_supplementary_angles.html\nloadExercise submod math\nloadExercise submod graphie\nloadExercise submod math-format\nloadExercise submod answer-types\nloadExercise submod tmpl\nloadExercise submod tex\nloadExercise submod jquery.adhesion\nloadExercise submod calculator\nloadExercise submod /khan-exercises/third_party/MathJax/2.1/MathJax.js?config=KAthJax-9e2776ffe7d2006f16f36d0d55d9464b\nloadExercise finish complementary_and_supplementary_angles.html\nMathJax done typesetting ( \\triangle CDE \\cong \\triangle ABC)\nMathJax done typesetting ( \\overline{AB} )\nMathJax done typesetting ( \\overline{DE} )\nMathJax done typesetting ( \\angle DCE \\cong \\angle BAC)\nMathJax done typesetting ( \\overline{CD} \\cong \\overline{AB})\nMathJax done typesetting ( \\cong )"}}