How do you find the area #(x - 2 )² + (y + 4 )² = 9#?
The area of the circle described by your equation is
#(x-2)^2 + (y + 4)^2 = 9#
describes a circle.
A standard circle equation for a circle with the center
#(x - h)^2 + (y - k)^2 = r^2#
Thus, in your case, the center of your circle is the point
If I understand your question correctly, you would like to compute the area of this circle.
The formula for that is
#A = pi r^2 = pi * 3^2 = 9pi ~~ 28.27 " units"^2#