Equations of Circles Write the equation of each circle. 1. center at origin, radius 6 2. center at (0, 0), radius 2 3. center at (4, 3), radius 9 4. center at (7, 1), diameter 24 5. center at (-4, -1), passes through (-2, 3) 6. center at (5, -2), passes through (4, 0)