Question 534131
The circle will be tangent to the line at a point with y=4.
The center of the circle is on the line x=-4.
The lines x=-4 and y=4 are perpendicular, like radius and tangent should be.
The segment on line x=-4 between circle center (-4,5) and the intersection with the tangent line y=4 is a radius of the circle.
The circle will be tangent to the line at the point (-4,4).
The length of the radius is 1.
The equation of the circle is
{{{(x+4)^2+(y-5)^2=1}}}
The circle looks like a little wheel of radius 1 (diameter=2) sitting on point (-4,4) on the horizontal line y=4.