Circle formula: (x - h)² + (y - k)² = r² ; where (h,k) is the vertex & "r" is the radius
Since the radius is 4, (x - h)² + (y - k)² = 4² → (x - h)² + (y - k)² = 16
1) If you have two points, replace "x" and "y" with the coordinates to create two equations with unknown variables "h" and "k".
2) Then solve the system to determine the value of "h" and "k".
3) Input the values of "h", "k", and "r" into the Circle Formula.
