Hello, I am drawing a polygon using other frame as reference (over it). So, the toogle snapping to nodes is usefut to reproduce the size that I want. But in one unique side, I must not handle to curp. I need to stop a little before the next node. I can't because the program automatically extend my side. 

If I disable in right side, I lose the drawing. Is it some way of disable it "during"  the drawing? A shortcut or other way?

I can't make the bevel of bus back side without lose the current drawing. 

When you move the cursor over the Snapping toggle you will see the shortcut "%". This allows to toggle on/off snapping during drawing.

@cimerio Hi, I see you are working with an object and I think it would be better to convert it to path and use the path effects corners option to make the bevels. You can do the bevel on all nodes at once or individually. This way you would have more control, I think. I leave you a little video to explain visually what I'm trying to say. Sorry for the mistakes.

Is this a Clipping Path you´re editing?

polygon, your method worked well. I made a video below showing it. actually, I am not trying editing, because I tried it before and failed. I was starting a bezier form (B) from zero.

Marcos, your solution is good too, but I don't know if it would work, because I need a straight line instead of a curve.

I just see kind of placeholder but no actually video?

Polygon

I just see kind of placeholder but no actually video?                     

Fixed it.

Thanks @TylerDurden

@cimerio You simply can snap to the corner - then take the node-tool, select the bottom left node - move it up with ctrl to be straight or with snapping to "Cusp node to Path" or use arrow keys.

@Polygon  oh, now I see that it's possible. because there are so 5 nodes instead of four. hahahahha. I never thought of that.