Measuring length/circumfernece of a shape

Hi everyone,

I am looknig at different intestinal cross sections of fishes, where I want to comapre intestinal surface.
There is a really cool drag and drop like plugin which allows to outline the inner shape of the intestine.
https://twitter.com/jmutterer/status/1371475178073509888
When now measuring (ctrl + m) the shape I only get the area of the shape and not the length (it says length = 0). I get the same result when just drag and dropping a circle or square so its not the plugin s fault.
My question now…is there a way to measure also the circumference/length of a shape?

Thank’s for your answers

~Z

with length/circumference do you mean perimeter?