**A circle is drawn with its center at (8,0) and with radius r such that the circle cuts the ellipse x^2 + 4y^2 = 16 at right angles. Find the radius of the circle ?**

**Answer:**

**A circle is drawn with its center at (8,0) and with radius r such that the circle cuts the ellipse x^2 + 4y^2 = 16 at right angles. Find the radius of the circle ?**

**Answer:**