Rotate object parallell to line

Question

Suppose I have an object A containing a line segment l. Now I have another line segment q in my drawing. How can I rotate the whole object A such that the line segment l becomes parallell to q?

I've done this manually by now, but it takes time and doesn't get exact.

PS: It's OK for me that the object A gets translated; A does not need to be at the same place after rotation.

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Answer 1

Node snapping will help. Enable the following from the node snapping toolbar:

1. Enable snapping %, the first button in the toolbar.
2. Snap nodes, paths and handles (important!)
3. Snap to paths
4. Snap cusp nodes
5. Snap smooth nodes
6. Snap other points...
7. Snap an item's rotation center (important!)

Some of the above snapping options may be unneeded, and depend on your path.

Now, select path A twice so you can see the rotation handles and the rotation center.

Drag the rotation center to one of the endpoints of line segment I; snapping should get you exactly there.

Now, drag the whole path so that the rotation center snaps to line segment q.

Now you can rotate path A so that the other endpoint of line segment I snaps to line segment q.

If q is too short compared to I, you can duplicate q and transform it into a guide (shifg-G). Now you can drag this guide and keep the angle. Snap to the guide rather than q (after enabling snap to guides).