Question

what is the radius of this circle?

Explanation:

Step1: Identify center and a point on circle

The center of the circle is at $(2, - 2)$ and a point on the circle is $( - 6, - 2)$.

Step2: Use distance formula for radius

The distance formula between two points $(x_1,y_1)$ and $(x_2,y_2)$ is $d=\sqrt{(x_2 - x_1)^2+(y_2 - y_1)^2}$. Here, $x_1 = 2,y_1=-2,x_2=-6,y_2 = - 2$. Substituting values: $r=\sqrt{(-6 - 2)^2+(-2+2)^2}=\sqrt{(-8)^2+0^2}=\sqrt{64}=8$.

Answer:

8