Secant line a circle in the Euclidean plane, a line joining two of them would be a 2-secant (or "bisecant") and a line passing through only one of them would be a 1-secant (or "unisecant"). A unisecant in this example need not be a tangent line to the circle. This terminology is often used in incidence geometry and discrete geometry. For instance, the Sylvester–Gallai theorem of incidence geometry states that if points of Euclidean geometry are not collinear then there must exist a 2-secant of them. And the original orchard-planting problem of discrete geometry asks for a bound on the number of
Magic circle for raising energy within the circle is by means of a cone of power. The barrier is believed to be fragile, so that leaving or passing through the circle would weaken or dispel it. This is referred to as "breaking the circle". It is generally advised that practitioners do not leave the circle unless absolutely necessary. In order to leave a circle and keep it intact, Wiccans believe a door must be cut in the energy of the circle, normally on the East side. Whatever was used to cast the circle is used to cut the doorway, such as a