If the area of the circle is 13, what is the radius?

Given that the area of a circle is 13 square
units.

We need to find the
radius.

To find the radius, we will use the formula of the
area of a circle.

We know
that:

A = r^2 * pi such that A is the area of the circle
and r is the radius.

Now we will substitute with the values
of the area.

==> 13 = r^2 *
pi

We know that pi = 22/7 or
3.14

==> 13 = r^2 *
22/7

Now we will multiply by 7/22 both
sides.

==> r^2 = 13*7/22 = 4.14 (
approx.)

Now we will take the square root of both
sides.

==> r =
2.03

Then, the radius of the circle whose
area is 13 is r = 2.03 units.