Khan/khan-exercises — Issue #15490: Quadrilateral types - Which sides are parallel?
Author: KhanBugz
Created: 2012-03-05 22:17:30+00:00
State: open
Labels: chrome, snowleo, wrong-or-unclear

Reporter: adam@masturbacon.com

I've tried splitting corners of this quadrilateral into 2 right-angled triangles, but when I do, then pythagoras gives me different heights at the 2 points (2.2*sin59=1.89 vs 2.0*sin66=1.83), so the lines cannot be parallel.

[quadrilateral_types.html?seed=9&problem=trapezoid](http://sandcastle.khanacademy.org/media/castles/Khan:master/exercises/quadrilateral_types.html?seed=9&problem=trapezoid&debug)

[Answer timeline](http://sandcastle.khanacademy.org/media/castles/Khan:master/exercises/quadrilateral_types.html?seed=9&problem=trapezoid&debug&activity=%5B%5B%22incorrect-activity%22%2C%22%5C%22Rhombus%5C%22%22%2C17%5D%2C%5B%22incorrect-activity%22%2C%22%5C%22None%20of%20the%20above%5C%22%22%2C3%5D%2C%5B%22hint-activity%22%2C%220%22%2C1%5D%2C%5B%22hint-activity%22%2C%220%22%2C2%5D%2C%5B%22hint-activity%22%2C%220%22%2C19%5D%5D)

["Rhombus","None of the above"]

Mozilla/5.0 (Macintosh; Intel Mac OS X 10_6_8) AppleWebKit/535.19 (KHTML, like Gecko) Chrome/18.0.1025.45 Safari/535.19

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