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
Dividing a circle into areas Dividing a circle into areas In geometry, the problem of dividing a circle into areas by means of an inscribed polygon with "n" sides, in such a way as to "maximise" the number of areas created by the edges and diagonals, has a solution by an inductive method. If we already have "n" points on the circle and add one more point, we draw "n" lines from the new point to previously existing points. Two cases are possible. In the first case (a), the new line passes through a point where two or more old lines (between previously existing points)