Question 317532
The sum of the exterior angles of any polygon is 360°.  Suppose the
polygon has n sides.  Since it is regular, all n exterior angles have
the same measure, so {{{"90°"n="360°"}}}, so {{{n="360°"/"90°"=4}}}
<pre><b>
It's a 4-sided regular polygon, so it's a square!:

{{{drawing(400,400,-2,2,-2,2, line(-1.5,-1,1,-1), line(1,-1.5,1,1), line(1.5,1,-1,1), line(-1,1.5,-1,-1), locate(-1.3,-.8,"90°")  



)}}}


Edwin</pre>