Draw solid color triangle using XAML only

Question

Is it possible to draw a filled in triangle using XAML only (not a code behind solution)?

Triangle should be like on the image below to represent sort direction Ascending/Descending along with a sort button on a chart control:

EDIT: The solution, thanks to SpeziFish:

Ascending:

<Polygon Points="0,0 8,5, 0,10" Stroke="Black" Fill="Black" /> 

Descending:

<Polygon Points="8,0 0,5, 8,10" Stroke="Black" Fill="Black" /> 

Answer 1

<Polygon Points="0,0 80,50, 0,100" Stroke="Black" Fill="Black" /> 

See API or Example.

Answer 2

I want to add these to their collection:

    <Polygon Points="5,0 10,10, 0,10" Stroke="Black" Fill="Black" /> 

    <Polygon Points="0,0 5,10, 10,0" Stroke="Black" Fill="Black" />