With some geometry
you so much

1).  The center of the circle is  (4, 2) .  Its radius is  5 .

2).  The center of the circle is  (-2, -1) .
       Its radius is  √32 = 4√2  =  about 5.66 .

3).   The center of the circle is  (0, 2) .  Its radius is 3 .

4).  The equation of the circle is     (x - 4)²  +  y²  =  9 .

To label a point on the circle:

-- pick any number less than the radius for 'x'
-- write it in the equation.
-- then solve the equation to find 'y' .

Now you have ' x ' and ' y '.  If you did it accurately, the point is on the circle.
You can mark a dot there and write the coordinates next to it.

A) for the n row: 22+(n-1)×6therefore,b) 100-22=78that means (n-1)×6=7878÷6=1313+1=1414th row has 100 seats