Hi ! I wonder if instead of :

checkio("(2,2),(4,2),(2,4)") == "(x-4)^2+(y-4)^2=2.83^2"

there should be something like:

checkio("(2,2),(4,2),(2,4)") == "(x-3)^2+(y-3)^2=1.41^2"

or maybe like (same as drawing):

checkio("(2,2),(6,2),(2,6)") == "(x-4)^2+(y-4)^2=2.83^2" ?