Role of a, b and r in the equation (x-a)^2+(y-b)^2=r^2

Author:
Mathguru
We can clearly see the graph of a circle with the equation (x-a)^2+(y-b)^2=r^2 in red color. If we change the values of a, b and r using their corresponding slide bars we will see that the position and size of the circle gets changed. Let us observe how the size and position of the circle changes as we change the values of a, b and r
Questions to think about 1. Compare the coordinates of the center ‘D’ with a and b, what do you observe? 2. Compare radius of the circle with r, what do you observe?