$\"\"$

The center of the circle is $\"\"$ .

The tangent line of circle is $\"\"$ .

The tangent line is a horizontal line.

Therefore, one end point of the circle is $\"\"$ .

The distance between center and one end point is the radius of the circle.

Distance between two points is $\"\"$ .

$\"\"$

$\"\"$ .

The standard form of circle is $\"\"$ .

Substitute $\"\"$ and $\"\"$ in $\"\"$ .

$\"\"$

$\"\"$ .

The equation of circle is $\"\"$ .

$\"\"$

Graph:

Graph the equation of circle is $\"\"$ .

$\"\"$

The equation of circle is $\"\"$ .

Graph:

Graph the equation of circle is $\"\"$ .

$\"\"$ .