Edit polygon

You can select the width of the border. The border width can be set to zero so it is not visible.

The color of the border,

And the fill color of the polygon, setting the transparency of the fill color to 100% will make it invisible.

Pressing the Close button will store the edited polygon properties and bring you back to the main sketch dialog.

The Cancel button will bring you back to the main sketch dialog, no changes will be made.

The Delete button will delete the selected polygon from the sketch.