Answer:
4.5 units
Explanation:
In this case, if we draw the point on the xy cartesian plane, we know that the value of "x" is 4.5 and the value of "y" is 0.
Which means that when I draw this in any way, the maximum value it will take is 4.5 units, therefore the radius should not exceed this value, nor should it be less than 4.5 units since the circle would be distorted.
Which means that the radius is 4.5 units