What is the radius of a circle whose equation is x2 + y2 + 8x – 6y + 21 = 0?

The center of the equation of the circle is (−4, 3) and the radius of the equation of the circle is 2.What is a circle?It is a locus of a point drawn equidistant from the center. The distance from the center to the circumference is called the radius of the circle.The equation of the circle is given below.x² + y² + 8x − 6y + 21 = 0Add 4 to both sides of the equationx² + y² + 8x − 6y + 21 + 4 = 4x² + 8x + 16 + y² − 6y + 9 = 4              (x + 4)² + (y − 3)² = 2²Then the center of the equation of the circle is (−4, 3) and the radius of the equation of the circle is 2.More about the circle link is given below.