corel has a plugin that allows you to draw a house to scale, and later measure it. including the square..
here is the link..
https://www.youtube.com/watch?v=iFNqTu9kWKM
(I found it only in Russian. but even if you don't know Russian, you can watch it without sound)
Tell me, someone can help make 2 similar functions in inkscape:
1. specify that the segment is 5 meters long, then specify the scale for it (to choose from or your own in the form 1:1, 1:10, 1:100 and so on)
2. Select an area limited by segments and create an inscription with its area at a given scale (for example, a 5*5 cm rectangle at a scale of 1:100 = 25 square meters, as well as at a scale of 1:50 = 6.25

1) not sure

2) I'd try Extension>Visualize Path>Measure>Area

It's magic!
This extension has both a scale and 2 area and even a length/area! (see picture 1)
Moreover, thanks to the adjacent "dimensions" extension, architectural dimensions can be made. (see picture 2)
1. but I did not understand whether it is possible to measure the lengths of individual faces?
how to count not the total perimeter, but to select 4 faces and specify the size of each of them?
can I ask you to add such a check mark to the extension? or is it possible?
2. how do I make sure that by default there are not arrows at the ends of the lines, but serifs?
3. The "dimensions" extension specifies an offset of 50.. pixels? is it possible to make a choice of units, as in the "measure contour" extension?
in any case, thank you very much!

Unfortunately, I noticed that the "measure" extension works correctly only for a rectangle:
if the sides of the shape are not equal, you need to highlight the segments with a dimensional line and show the numerical size of each of them.
and show at what scale.

now even one single segment cannot be measured..
It may be necessary to provide a mode for measuring the lengths of segments along their normal

I'd try Path>Path Effects>Measure>segments: