How many sides does a exterior angle of 1620 degrees have?

To determine the number of sides of a polygon based on its exterior angle, you can use the formula ( n = \frac{360}{\text{exterior angle}} ). For an exterior angle of 1620 degrees, you calculate ( n = \frac{360}{1620} ), which simplifies to ( n = \frac{1}{4.5} ). Since ( n ) must be a whole number, a 1620-degree exterior angle does not correspond to any polygon with a finite number of sides.