1. Make two circles, one smaller than the other.
2. Make sure the smaller circle is higher than that other (Object menu > Raise to Top)
3. Center the circles on each other
4. Select both circles > Path menu > Difference
The Inkscape *.svg file format is an xml format.
This editor let's you edit that xml directly.
Edit menu > XML Editor
Note that all measurements are in a default and cannot be changed.
You cannot edit in the XML Editor using pixel units.
An empty project always starts with an empty layer.
<svg:g id="layer1" inkscape:label="Layer 1">
</svg:g>
Clicking on a line in the editor will select that element in the main pane.
Attributes for the selected element are shown in the right-hand pane.
You can edit the attibute values.
To add an attribute:
1. Type the attribute name in the upper-right input field
2. Type the attribute value in the lower-right input field
3. Click "Set"
To see all the attributes valid for each element, see the official standard:
[Scalable Vector Graphics]