Normal (geometry) Normal (geometry) In geometry, a normal is an object such as a line or vector that is perpendicular to a given object. For example, in two dimensions, the normal line to a curve at a given point is the line perpendicular to the tangent line to the curve at the point. In three dimensions, a surface normal, or simply normal, to a surface at a point "P" is a vector that is perpendicular to the tangent plane to that surface at "P". The word "normal" is also used as an adjective: a line normal to a plane, the normal component
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)