Khan/khan-exercises — Issue #6729: Congruency postulates - congruency postulate issue realized
Author: KhanBugz
Created: 2011-11-20 02:29:56+00:00
State: open
Labels: chrome, win7, wrong-or-unclear

Reporter: atheistkkharm@gmail.com

http://imgur.com/vPVOd
http://imgur.com/vitmN
(image above from the same problem)

I realized what the problem is. On a SSA triangle with flash animation there seem to be at least two configurations you can put the triangle in to get a incongruent triangle. However the website only delivers a right answer if you happen to picked the right configuration of the two.

Put simply the website is checking your configuration of the triangle against some template. I think the fact that there are two possible configurations in an SSA triangle has been missed. So either both templates need to be added or some code needs to be added to simply check to see if all the vectors are snapped together.

I hope this helps. I love your site btw and keep up the good work.

[congruency_postulates.html?seed=10&problem=0](http://sandcastle.khanacademy.org/media/castles/Khan:master/exercises/congruency_postulates.html?seed=10&problem=0&debug)

[Answer timeline](http://sandcastle.khanacademy.org/media/castles/Khan:master/exercises/congruency_postulates.html?seed=10&problem=0&debug&activity=%5B%5B%22correct-activity%22%2C%22%5B%5C%22No%5C%22%2C%5B-1.888788552547568%2C1.9746708316608372%5D%2C%5B-4.9859942688465155%2C2.2316578934521147%5D%2C%5B-0.51774076958948%2C6.015226036749105%5D%2C%5B-1.888788552547568%2C1.9746708316608372%5D%5D%22%2C30%5D%2C%5B%22correct-activity%22%2C%22%5B%5C%22No%5C%22%2C%5B-2.442374692006398%2C0.512763990703007%5D%2C%5B-5.040991629612372%2C2.217438625520555%5D%2C%5B-0.5384919251976932%2C5.960188101552889%5D%2C%5B-2.442374692006398%2C0.512763990703007%5D%5D%22%2C162%5D%5D)

[["No",[-1.888788552547568,1.9746708316608372],[-4.9859942688465155,2.2316578934521147],[-0.51774076958948,6.015226036749105],[-1.888788552547568,1.9746708316608372]],["No",[-2.442374692006398,0.512763990703007],[-5.040991629612372,2.217438625520555],[-0.5384919251976932,5.960188101552889],[-2.442374692006398,0.512763990703007]]]

Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/535.2 (KHTML, like Gecko) Chrome/15.0.874.120 Safari/535.2

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