Set line length in Inkscape

Question

I want to set the length of the red line to be 0.5". (Actually, the svg doesn't export the red, so let's say the one that points to 4 o'clock.)

How do I do that?

Answer 1

Another, possibly quite precise option, using the measurement tool:

https://youtu.be/lcYv5dLTScU

Answer 2

Create an orthogonal reference line of approximate desired length
(hold Ctrl while creating line) and adjust as needed in the appropriate width field:

Note: size in mm equals one-half inch

• change color and increase width of stroke for ease of use,

• reduce opacity for the same reason,

• place a new line on a separate layer for ease of destruction

• drag horizontal and vertical guides to intersect node of line at static end

  Note: ensure that the guides are intersecting the node/snapping to them

• drag a new line to snap to the line to be changed at static end

• click on new line to change to rotate mode (note pivot crosshairs)

• drag pivot crosshairs to intersection of guides

  Note: use maximum zoom to ensure the rotation center is on the node/guide intersection. I've not been able to locate a resource which permits the rotation center to snap to anything.

Note that the rotation center is not at the guide intersections, as it disappears when placed there. For the purposes of this presentation, it's close enough to see and the answer states to place it on the dot, so to speak.

• rotate the new line at optimum zoom to align with existing line

There is no snapping going on here, but at a good zoom level, one can use TLAR to ensure that the lines are parallel. (That looks about right).

• select existing line in node edit mode

• snap existing line end to the new line end

I've rotated the newly adjusted line to horizontal by eyeball and note that the dimension field shows the desired 12.7 mm length.

• delete layer/new line as desired

There may be an easier/better way to accomplish this. My first thought was to create the line length necessary and place and rotate it, but that's not how the question is phrased.

One could eliminate the guides, but that reduces a bit the "precision" available to place the rotation crosshair, especially at maximum zoom.

Answer 3

Take the following steps:

1. Start with a line segment that is longer than it should be.
2. Create a circle whose radius equals the desired length.
3. Use snapping to position the center of the circle at the end point of the line segment that should not be cut off.
4. Make sure the circle is "above" the line you want to cut, in terms of Z-order. Normally it already is when you draw the circle later. If not, select the circle and press the Home key on your keyboard, or go into the Object menu and click on "Raise to top".
5. Select the circle and the line.
6. Go into the "Path" menu and select "Cut path". The circle will vanish and the line segment is cut into two pieces: one with the desired length and the remainder.
7. Delete the remainder.