Length of Line Segment Between Points on a Circle

In the coordinate plane, consider a circle defined by the equation $$x^2 + y^2 = r^2$$, where $$r$$ is the radius of the circle. Two points are defined: Point A at coordinates $$(r, 0)$$ and Point B at coordinates $$(0, r)$$. If a line is drawn from Point A to Point B, what is the length of this line segment in relation to the radius of the circle?