[x] Polygon Outline
When checked, the polygon will have an outline
Color and Width define the color and width in [mm] of the outline.
[x] Polygon Fill
When checked, the polygon will have a fill
Color defines the color of the fill, the Fill Alpha slider can be set to set the transparency of the fill. Fully opaque = 255, fully transparent = 0 (this would correspond to switching off the polygon fill completely.
[x] Preserve aspect ratio
When checked, the polygon will preserve it's aspect ratio whenever the user resizes the shape.