If a circle of radius 2 is made to roll along the x-axis, what is an equation for the path of the center of the circle?

The area of the circle is equal to pi multiplied by the square of the radius. the general equation that represents the equation of the circle is x^2  + y^2 = r^2. r is equal to 2 such that r^2 is equal to 4. hence the equation becomes
x^2  + y^2 = 4

20000 as first it increases by 2500 then by 5000 so next it will increase by 10000