Answer
Refer to the picture below for the graph
Work Step by Step
$\sqrt{25 - x^2} = y$
$25 - x^2 = y^2$
$x^2 + y^2 = 25 = r^2$
$r^2 = 25$
$r = 5$
Now, knowing the radius of the circle, we can now draw the circle as shown in the picture below