algebra 1
posted by elodie on .
In the standard (x,y)cooridniate plane the graph of (x2)second power +(y+4 second power =9 is a circle. What is the area enclosed by this circle, expressed in sguare coordinate units?
please help me?

recall that the equation of a circle is given by
(xh)^2 + (yk)^2 = r^2
where
h = xcoordinate of center of circle
k = ycoordinate of center of circle
r = radius
thus from the given equation,
(x2)^2 + (y+4)^2 = 9
the radius is sqrt(9) = 3
also, recall that area of circle is given by
A = pi*r^2
substituting,
A = pi*(3)^2
A = 3.14*9
A = 28.26 square units
hope this helps~ :)