I'll just ignore this silliness.
I'm willing to bet that initially when someone discovered pi they did so by measuring the circumference and diameter of a circle and then dividing one by the other.
I'm also willing to bet that Pythagoras didn't just "reason" his theorem but actually looked at right triangles.
To be quite honest I don't fully understand why you find this sort of point meaningful. It's like saying the verb "run" isn't based in reality because it is a concept.
This is silliness to the extreme. And doesn't really support the idea that morality must ipso facto be from outside of space and time.
And, again, do you think that some intelligence beyond space and time had to "invent" the fact that the ratio of a circle's circumference and diameter equaled pi? Or is it more akin to 1+1=2. It is simply what a circle is. Almost tautological if you will.
In your imagination can you imagine a world in which a circle can be drawn that doesn't have that ratio?
It most assuredly DOES exist physically.
You don't think very much about truth and knowledge. Perhaps you lack imagination to even ask the right questions.
Humans cannot draw pristine perfect circles. There is always some tiny margin of error even in precision graphics.
There aren't perfect, ideal circles floating in space.
Therefore, you cannot physically represent an ideal pi.
Further no one actually knows what the value of pi actually is, because it's an irrational number and the world's most powerful computers can only represent an
approximation of pi to a finite number of digits.
The concept of pi was objectively true ten billion years before humans drew circles. It will be objectively true ten billion years after our extinction.
Pi, in it's actual and ideal form, is an abstract and objectively true concept humans only discovered through our gift of reason. It was always an abstract and transcendental concept, even when we try to approximate it's real form on paper or computer calculation.
Things ideas, concepts can be objectively true, even if they don't exist physically. Period, end of story.