Secant line Secant line In geometry, a secant of a curve is a line that intersects the curve in at least two (distinct) points. The word "secant" comes from the Latin word "secare", meaning "to cut". In the case of a circle, a secant will intersect the circle in exactly two points and a chord is the line segment determined by these two points, that is the interval on a secant whose endpoints are these points. A straight line can intersect a circle in two, one or zero points. A line intersecting in two points is called a "secant line", in one
Circle of antisimilitude Circle of antisimilitude In inversive geometry, the circle of antisimilitude (also known as mid-circle) of two circles, "α" and "β", is a reference circle for which "α" and "β" are inverses of each other. If "α" and "β" are non-intersecting or tangent, a single circle of antisimilitude exists; if "α" and "β" intersect at two points, there are two circles of antisimilitude. When "α" and "β" are congruent, the circle of antisimilitude degenerates to a line of symmetry through which "α" and "β" are reflections of each other. If the two circles "α" and "β" cross each other, another two