1 - Determine the equation of the circumference
whose center is at the coordinate C (3, 3) and
radius 4.
2 - Determine the equation of the circumference
whose center is at the coordinate C (1, -1) and
radius 3.
3 - Determine the value of the radius (r) and the
equation of the circumference that passes through
the point P(0, 2) and have the center
at the coordinate (0, 0).