In details

Position of a line relative to a circumference


Given a straight s: Ax + Bx + C = 0 and a circumference of equation (x - a)2 + (y - b)2 = r2, let's examine the relative positions between s and :

We can also determine the position of a line relative to a circle by calculating the distance from the line to the center of the circle. So given the line s: Ax + By + C = 0 and the circumference : (x - a)2 + (y - b)2 = r2we have:

Like this:

Next: Tangent Conditions Between Line and Circumference