Circle primitive Bmesh or object size

if I add a circle diam = 10 with script or as object in viewport
then add another circle pentagon at same location

the diam of circle is not the same then the pentagon
circle is = 10 pentagon = 9.511

why is pentagon not the same size = 10 ?

thanks for any feedback
happy bl

So there good question. . . in addition I am not too mathematical … :blush:

But personally, I don’t see the problem!
Your Pentagon Circle is indeed a circle with only 5 sides and if I put them one above the other, it seems consistent to me.
Pentagone

N panel shows only the box object size

and pentagon is smaller then the circle in dim

but points are on the circle
to see this you need to add like 1000 segments LOL

thanks
happy bl

I repeat, I am not an ace of mathematics. . . and maybe I just don’t quite understand your question … :smiley:

IMO, for me the pentagon has the same diameter as the circle. . . . just measure it.

ok what is happening with images !

happy bl

i’m doing high precision calculs
and in the viewport I was adding a pentagon inside a circle
and when you zoom in very close the pentagon points did not fit precisely on the circle.

it depends also on the number of segments for the circle.

thanks for feedback
happy bl