**complete quadrilateral** — noun : a figure that is determined by four coplanar lines, and has four sides and three diagonal axes, each two of which cut the other harmonically in three centers of which one or even two may be at infinity * * * Geom. a plane figure composed… … Useful english dictionary

**complete quadrilateral** — Geom. a plane figure composed of four straight lines and their points of intersection. * * * … Universalium

**Quadrilateral** — Quad ri*lat er*al, n. 1. (Geom.) A plane figure having four sides, and consequently four angles; a quadrangular figure; any figure formed by four lines. [1913 Webster] 2. An area defended by four fortresses supporting each other; as, the Venetian … The Collaborative International Dictionary of English

**Complete quadrangle** — A complete quadrangle (at left) and a complete quadrilateral (at right). In mathematics, specifically projective geometry, a complete quadrangle is a system of geometric objects consisting of any four points in the Euclidean plane, no three of… … Wikipedia

**Golden Quadrilateral** — The Golden Quadrilateral (GQ) is the largest express highway project in India launched by former prime minister Atal Bihari Vajpayee. It is the first phase of the National Highways Development Project (NHDP), and consists of building 5,846… … Wikipedia

**History of trigonometry** — The history of trigonometry and of trigonometric functions may span about 4000 years.EtymologyOur modern word sine is derived from the Latin word sinus , which means bay or fold , from a mistranslation (via Arabic) of the Sanskrit word jiva ,… … Wikipedia

**Configuration (geometry)** — Configurations (4362) (a complete quadrangle, at left) and (6243) (a complete quadrilateral, at right). In mathematics, specifically projective geometry, a configuration in the plane consists of a finite set of points, and a finite arrangement of … Wikipedia

**Nasir al-Din al-Tusi** — Persian Muslim scholar Naṣīr al Dīn al Ṭūsī The Astronomical Observatory of Nasir al Din al Tusi Title Khawaja Nasir … Wikipedia

**Menelaus' theorem** — Menelaus theorem, case 1: line DEF passes inside triangle ABC Menelaus theorem, named for Menelaus of Alexandria, is a theorem about triangles in plane geometry. Given a triangle ABC, and a transversal line that crosses BC, AC and AB at points D … Wikipedia

**Duality (mathematics)** — In mathematics, a duality, generally speaking, translates concepts, theorems or mathematical structures into other concepts, theorems or structures, in a one to one fashion, often (but not always) by means of an involution operation: if the dual… … Wikipedia