Question 341458: if the sum of the interior angles measure of a polygon is 1440 degrees, how many sides does the polygon have? Answer by Alan3354(69443) (Show Source):
You can put this solution on YOUR website! The sum of the interior and exterior angle at each vertex = 180 degs
The sum of the exterior angles for ALL polygons = 360 degs
Add 360 to 1440 = 1800 degs
1800/180 = 10 sides
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The usual method:
Sum of interior angles = 180*(n-2) = 1440
180n - 360 = 1440
180n = 1800
n = 10
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Add 360 to the interior total, divide by 180, either way.
