i think it has something to do with the exterior angle thorem but im not really sure
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each of these angles is supplementary to each of the interior angles of the triangle.
so their sum is $3\pi - \pi = 2 \pi$
The sum of the exterior angles of any convex polygon is $360^\circ$
this is not a polygon tho its a triangle . where you add up the angles of the straight lines i get 540 degrees and then i take away 360 cause thats the amount of degrees in a triangle and then im left with 180 .
this is not a polygon tho its a triangle
fyi ... a triangle is a 3-sided polygon.
Last edited by skeeter; Dec 23rd 2016 at 07:51 AM.
thanks for the diagram i understand it now