need help quick

Each angle of a regular polygon is 160 degrees.  How many sides does it have? 

Since each interior angle is 160^o that means the associated exterior angle is 20^o 

Since the total of the exterior angles of any polygon is 360^o that means there are 18 of them

Since there are 18 angles, then there are 18 sides 

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If the interior angle of a regular polygon is 160 degrees, then the exterior angle is 20 degrees. The sum of all exterior angles is 360 degrees so there must be 360/20 sides = 18 sides.