Question 1112410
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I thought that those who knew it once, would never forgot it . . . 



<pre>
The exterior angle = 180 degs - 160 degs = 20 degs.


The sum of all exterior angles = 360 degs  ====>  the number of sides/vertices = 360/20 = 18.
</pre>

<U>Answer</U>. 18 sides.