Answer:
equation of a circle with center at (0,3) and radius of 1 is
x² + (y-3)² = 1
equation of a circle with a center at (-6, 9) and a radius of 12 is
(x + 6)² + (y - 9)² = 144
equation of a circle with center at (0,0) and a radius of 2 is
x² + y² = 4