I need to create a perfect circle with the bezier tool and not with the circle tool. The purpose of this is to later animate my svg with css.
When drawing a citcle in Inkscape then this will be its path :
To convert this path to Bezier lines just select the object, then choose Path > Object to Path:
We can now insert nodes, break paths or whatever there is we need to do (below example was obtained by inserting 3 nodes and deleting the path between two selected nodes):
ellipse tool, draw a circle (with 'Ctrl') and now - with the
ellipse toolstill selected - hover over the 3 visible nodes of the circle and read the hints in the status line: you can position the start and end point of the circle to create a segment, and with the toggle on the ellipse controls bar you can determine if it's a segment (closed, filled path including the center) or an arc (unclosed shape).
Taken from This Post on the Inkscape forums.