How do I find the radius of a circle from the given equation?

Question

Find the equation of the circle tangent to the x-axis with center (8, -3)

I'm really confused on how I get the radius to use in the following step

(x-h)^2 + (y-k)^2 = r^2

From my knowledge so far, I can make it look like this, but no farther

(x-8)^2 + (y+3)^2 = R^2

HELP

Answer 1

for the radius part, you just need to find the point on the x-axis that is closest to the center (8, -3). so it would be drawing a perpendicular line from (8, -3) to the x-axis, and finding the intersection, which is (8, 0). then you find the distance between these two points. [(8-8)^2+(0-3)^2]^(1/2) = 3. 3 = radius.

Answer 2

As the x axis is tangent to the circle the distance of its center equals the radius.But this distance is the absolute value of the ordinate .So r=3

Answer 3

radius=3