Quadrilateral -1

Can you guess which one is the largest highway project in India? Don’t worry, I am giving you a clue. This is the project started in 2001 by the PM Atal Bihari Vajpayee. See the map below and concentrate on a mathematical term emerging out from this map. One more thing about this project is that in this project four major metropolitan cities – Delhi, Mumbai, Kolkatta and Chennai will be linked with each other.

Source: - National Highway Authority in India

Don’t worry, Let me tell you the name of this project so that you can guess the topic we will discuss now in details. The name of this project is Golden Quadrilateral.
The above examples are enough to show that quadrilateral is a geometrical shape that consists of four edges (Sides) and four vertices (corner).Quadrilaterals, like triangles are the second most common shape used in geometry. It is a geometric shape that consists of four vertices sequentially joined by straight line segments.
The word ‘quadrilateral is derived from the two Latin word – quadri and latus. The first word quadri means four whereas the word latus refers for side. In other words, quadrilateral is a figure having four sides.
According to the Merriam- Webster Dictionary a quadrilateral is a geometrical shape having four sides. The Collins Dictionary defines quadrilateral as a polygon having four sides and a complete quadrilateral consists of four lines and their six points of intersections. The other words sometimes used for quadrilateral are quadrangle and tetragon.
A quadrilateral is generally of three types – Convex quadrilateral, Concave quadrilateral and Simple quadrilateral.
A quadrilateral that has an angle more than 1800 is called Concave Quadrilateral. A quadrilateral is called simple if the four sides of a quadrilateral meet at vertices. Here we shall only focus on convex quadrilateral where each angle is less than 180.

Dr Rajesh Kr Thakur
rkthakur1974@gmail.com