Find the area of the circle x^2+y^2 - 2x + 8y = 13

Given the equation of the circle is
:

x^2 + y62 - 2x + 8y = 13

We
need to find the area.

First we need to determine the
radius.

Then, we will rewrite the equation into the
standard form.

(x-a)^2 + (y-b)^2 =
r^2

To convert, we will need to complete the
square.

==> x^2 - 2x + 1 -1 + y^2 + 8y + 16 - 16 =
13

==> (x-1)^2 + (y+4)^2 = 13 + 16 +
1

==> (x-1)^2 + (y+4)^2 =
30

Then the radius is the circle is
sqrt30.

Now we will calculate the
area.

==> A = r^ 2* pi = sqrt30^2 * pi = 30*pi =
94.25

Then, the area of the circle is 30pi =
94.25 square units.