Complete Quadrangle

In mathematics, specifically projective geometry, a complete quadrangle is a system of geometric objects consisting of any four points in a plane, no three of which are on a common line, and of the six lines connecting each pair of points. Dually, a complete quadrilateral is a system of four lines, no three of which pass through the same point, and the six points of intersection of these lines. The complete quadrangle was called a tetrastigm by Lachlan (1893), and the complete quadrilateral was called a tetragram; those terms are occasionally still used.

Read more about Complete Quadrangle:  Diagonals, Projective Properties, Euclidean Properties

Famous quotes containing the word complete:

    Thus when I come to shape here at this table between my hands the story of my life and set it before you as a complete thing, I have to recall things gone far, gone deep, sunk into this life or that and become part of it; dreams, too, things surrounding me, and the inmates, those old half-articulate ghosts who keep up their hauntings by day and night ... shadows of people one might have been; unborn selves.
    Virginia Woolf (1882–1941)