You can put this solution on YOUR website! ABCDEFGHIF is a regular decagon
Find m angle ABC
angleXBC is an exterior angle at vertex. Find m anleXBC
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There's a 2nd F, I'll assume it should be a J.
The sum of interior angles in any polygon with n sides is:
(n-2)*180
For 10 sides = 1440 degrees
Each angle is 1440/10 = 144 degrees
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The exterior angle is 180 - 144 = 36 degrees
