This problem can be equated to the ratio of the area of ??the square to the area of ??the circle.
Suppose the radius of the circle is r, then the area of ??the circle is π times the square of r, and the maximum square area is 2r.
Then, the probability of the dart hitting the square is 2/π, and the probability of not hitting the square is 1-2/π, which is approximately equal to 36.31%