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Math Help - About polygons problem

  1. #1
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    About polygons problem

    About polygons problem-0003.jpg
    How to prove that a+b+c+d+e = 540?
    Can anybody help? Thanks
    Last edited by william24; August 20th 2012 at 07:42 PM.
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  2. #2
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    Re: About polygons problem

    Quote Originally Posted by william24 View Post
    How to prove that a+b+c+d+e = 540?
    Can anybody help? Thanks
    1. The sum of the interior angles of a polygon with n vertices (n> 2) is calculated by:

    p+q+r+s+t = (n-2) \cdot 180^\circ

    Therefore the sum of all interior angles of a pentagon is 540.

    2. Now make a table:

    a = 360 - p
    b = 180 - q
    ...
    e = 180 - t

    Now calculate a + b + ... + e using the fact that you know p + q + ... + t already.


    By the way: You constantly post your question in the wrong forum. Why?

    You have posted a lot of questions but never have shown any form of own work. Why?
    Attached Thumbnails Attached Thumbnails About polygons problem-aussenwinkelsumme.png  
    Thanks from william24
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