I'm after some functionality in Inkscape but unfortunately I don't know what it's called, but I will try to describe it:

1. I draw a polyline (a path of straight line segments with a few nodes).
2. I use the node tool to grab one of the nodes and reposition it.

Currently in Inkscape when I do (2) the line segments either side of the node adjust their lengths to accomodate the new position of the node.

What I'm after is where the entire line is treated as if the segments were *rigid* (i.e. fixed length) and think of the nodes as hinges. So I drag one of the nodes to a new position, and by virtue of the fixed length line segments the rest of the line is dragged with the node, to some extent.

For example you could imagine if I had a straight line with two segments and nodes A/B/C:

(A) --- (B) --- (C)

If I grab (B) and drag it upwards, this is what Inkscape does (on the left) compared to what I want (on the right):

        (B)            |       (B)
        / \            |       / \
       /   \           |      /   \
      /     \          |     (A)  (C)
     /       \         |
    /         \        | 
   /           \       | 
  /             \      | 
(A)            (C)     | 

(it renders OK for me in monospace)

On the left, the segments AB and BC are lengthened and A and C remain in their original positions.
On the right, AB and BC preserve their length, and as a result the entire line is dragged upwards.

The particulars of exactly how (A) and (C) reposition themselves is not important to me, as long as they act in a way consistent with AB and BC having the same length before and after.

1. what is this feature called (so I can ask about it/search for it better)? 
2. Does Inkscape support this? (say I can toggle between the fixed-length and variable-length modes)?