Steps: The equation of a circle is (x – h)² <span>+ (y – k)</span>²<span> = r</span>²; since we are trying to find the radius we are going to focus on the r². Now if you look the equation has the 36 filled in as the r² so r² = 36; we now have to isolate the r to get the radius, how do we get the radius? We Square root the r² and 36. After we get r = 6, The radius is 6 units