SOLUTION: Find the measure of one interior angle of a regular polygon if the exterior angle has a measure of 120 degrees.

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Find the measure of one interior angle of a regular polygon if the exterior angle has a measure of 120 degrees.
The sum of an ext angle and an int angle is 180 degrees.
180 = ext + int
180 = 120 + int
60 degrees = interior angle
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The sum of the ext angles are 360.
360/120 gives us 3 sides ... a triangle