Today I got to use crop/inked from metapict/crop to automatically reduce the size of picts, which had blanks areas.

Thanks for pushing me to write it in the first place!

Is the angle marking at A too small compared to the right angle marking at C?

Looks okay to me. The area is not the same for sure, but the length along the sides of the triangle are the same I suppose?

Yes, the “radius” is the same.

Then i’d say that’s fine. The rest is optical illusion ;)