Drawing a Pentagon Polygon in XAML

Posted on October 01, 2016

I found myself needing to draw a pentagon in XAML and couldn't find the x and y coordinates for a pentagon polygon.
It wasn't exactly straight forward to work out so I thought i'd share my findings.

Oddly, I was unable to find some existing sample coordinates online, however I stumbed upon the formula for calculating them here.


Pentagon x,y coordinates

Pentagon x,y coordinate formula

But weirdly it doesn't seem to actually show the resulting coordinates in the maths equations, so I worked them out myself.

Pentagon coordinate calculation

0,1 0.95,0.309 0.588,-0.809 -0.588,-0.809 -0.95,0.309

However, if you put those coordinates into a XAML polygon control, you'll get an upside down polygon. So you'll need to reverse all the Y coordinates, making negative positive and positive negative.

0,-1 0.95,-0.309 0.588,0.809 -0.588,0.809 -0.95,-0.309

The resulting xaml is below.

Pentagon XAML

Which gives a resulting pentagon that looks like this.

Resulting Pentagon

Ignore some of the lines in the screenshot, they are because I put the polygon in a Viewbox element.