I have a simple diagram that includes a line going down at an angle, down and to the right at an angle of, say, 30 degrees below the horizontal. It is a straight line. I would like to add some text just above this line and have it aligned to the line.
I see how text can be included on a diagram either horizontally or vertically, but nothing else.

Is it possible to include text on a diagram that is at an angle? If so, how is it done?

Hi

Is it possible to include text on a diagram that is at an angle? If so, how is it done?

You will be amazed of all the possibilities in Inkscape.
There are many ways to do this, here's what I would do; (one of zillion ways to do this)
Type the text,
Select the text object by first pressing F1 to get into "object selection mode" - then left click with mouse. (everything on your page (or "canvas" in Inkscape terminology) is an object)
Click the selected object once more to get the rotation handles, (In the corners of the "selection box" - the green arrow with mouse pointer in example below)
"Grab" one handle and move mouse to rotate. By holding the ctrl key down while rotating the rotation will be in steps 15° increments (depending on what's set in your preferences).
( The text will rotate around the "rotation center" denoted by the small "cross" in the middle of the example image - this rotation center can be moved. )

After the rotation click the text object again to get the drag handles" - then click (and hold) left mouse button to move.
To align - see below.



If you see any of "brynn's" posts there are links in her signature to some fine tutorial's for beginners, it's highly recommended to spend some time with a few of those!
Recommend ]to take a look at this; http://tavmjong.free.fr/INKSCAPE/MANUAL/html/ - or better still - get a hardcopy!
There are a lot of ways to align objectsl - they are also covered in the tutorials

Good Luck
RGDS
Ragnar

Great! Thank-you very much!

Another question relating to text: is there a way to create subscripts and superscripts?
For example, the chemical formula for water is H₂O. At the moment I create the big letters in size 36 font and the small number in size 18 font. Then I move them closely together and make it look like the text is H₂O. It seems like a roundabout way to fake a subscript. Is there a better way? (Then, I plan to rotate this text as per your directions above, grabbing all three characters at once if I can.)

Hi.

The "Sub or Super" tools are on the toolbar when you got the text object (F8) - or - open.

Highlight the text you want to "Sub or Super" - Click the toggle Sub or Superscript icon on the text toolbar.



Good Luck again
RGDS
Ragnar