Layout dimension question

How do I get an accurate dimension on the attached view? More details are on the attachment.
Thanks in advance
Dave

Right End.layout (54.5 KB)

Would this work?

The first thing I did was fix your model. I set up scene 1 to Parallel Projection so it could be accurately dimensioned. Then, after I updated the scene and saved the file, I updated the reference and reselected Scene 1 for the viewport. You had modified the viewport breaking the connection to the original scene. I set the scale to 1:1 and then added the dimensions. Since your angular dimensions weren’t right, I replaced them, too.

Ok, is setting to parallel projection required all the time for dimensioning? Looks like I need to read up on that.
I have duplicated you method. Were you holding the left mouse button when the dim was placed?
Thanks for the lesson.
Dave

Required might be a slightly strong word. It certainly makes it easier to get the dimensions done correctly.

No. Click and release for the first end, click and release for the second end, move the cursor over, click and release to place the dimension.