The first comment is about the constant Tau.

I never heard of Tau so I had to look it up and came across this: "pi is a confusing and unnatural choice for the circle constant."

So now I am confused.

If a cicle has a diameter of 1 the circumference is pi.

Can someone explain in what context pi might be confusing?

Because the sinus/radians always relates to the radius instead of the diameter?