Equation of Circle/Cartesian/Formulation 3

Equation of Circle in Cartesian Plane: Also presented as
The equation of a circle with radius $R$ and center $\tuple {a, b}$ embedded in the Cartesian plane can be expressed as:
 * $x^2 + y^2 - 2 a x - 2 b y + c = 0$

where:
 * $c = a^2 + b^2 - R^2$