How to measure the plot

I have a code that outputs a circular plot. Which is supposed to be 50 mm in diameter. But I still want to measure it. Are there any measurement tools like the CAD softwares have?

Answer 1

[Walter Roberson]

You cannot measure diameters in software, not without additional hardware (such as a video camera focused on the screen.) Just pick up a tape measure and find its longest axis.

Then resize the window and see if the size gets adjusted -- if the size of the item changes (e.g., expands as the window expands in size) when the window size changes, then the diameter of the original circle was unlikely to have been accurate.