SOLUTION: How do I calculate the sum of the Interior angles of a convex 18-gon

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Question 98401: How do I calculate the sum of the Interior angles of a convex 18-gon
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
The sum of the exterior angles has to be 360 degrees.
360/18 = 20 degrees is the size of each exterior angle.
Each corresponding angle is the supplement of 20 or 160 degrees
There are 18 exterior angles of 160 degrees each.
18*160 = 2880 degrees is the sum of the exterior angles.
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Cheers,
Stan H.