Question

Each exterior angle of a regular polygon measures 20. How many sides does the polygon have?

Answer 1

`18` sides

Explanation:

A very useful property to know of any polygon, whether regular or irregular, is that the sum of the exterior angles is always 360°.

For a regular polygon, the size of each exterior angle, `theta` can be found from:

`theta = (360°)/n" "larr` where n = number of sides

Using this property, if you know the size of the exterior angle, you can find the number of sides.

`n = (360°)/(20°)`

`=18` sides