Its worth noting here that unless you follow Anssi's advice and create a circle with a number of sides divisible by 4, there will be NO point along any line or vertex in the circle that will correspond to the quadrant. Even referencing the center point of the circle and drawing out a radius to the edge will give you a smaller radius than the actual circle.
In Jean's example, the rotated circle/rectangle scenario only works because the circle was drawn orthogonal to the axis originally and then rotated afterward with the rectangle