The Math Forum



Search All of the Math Forum:

Views expressed in these public forums are not endorsed by NCTM or The Math Forum.


Math Forum » Discussions » sci.math.* » sci.math

Topic: Geometry Problem
Replies: 17   Last Post: Feb 20, 2008 10:04 AM

Advanced Search

Back to Topic List Back to Topic List Jump to Tree View Jump to Tree View   Messages: [ Previous | Next ]
rb

Posts: 1
Registered: 2/18/08
Re: Geometry Problem
Posted: Feb 18, 2008 5:46 PM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply

Kaba ha usato la sua tastiera per scrivere :
>> Hi all,
>>
>> I need help with this problem:
>>
>> http://img180.imageshack.us/img180/8286/20080218181526nq7.gif
>>
>> The angle to find is ECD.
>>
>> The matter is solving it without trigonometric functions.
>> With trigonometry or by drawing it you can see that the angle to find is
>> 20° (sessagesimal) but I can't find it using a simple solution (properties
>> of triangles, the parallel postulate and so on).
>>
>> Can you solve it?

>
> Interesting problem, couldn't solve it either. I get 4 unknowns but only 3
> linearly independent equations.


I'm not sure if an equation system is needed. I guess drawing a few
parallels and looking for properties like angle bisector theorem,
Thales' theorem, etc... should do the trick by showing two similar
triangles.

Anyway, I don't have any hint, this is only my approach so it could
also be wrong ;)





Point your RSS reader here for a feed of the latest messages in this topic.

[Privacy Policy] [Terms of Use]

© The Math Forum at NCTM 1994-2017. All Rights Reserved.