Descriptive geometry

Branch of geometry Example of four different 2D representations of the same 3D object Example object and its six principal views Different orthographic projections of a house. The file below shows three principal views and one that shows the true lengths in the plane of the roof. (The conic dormer shows parts of an ellipse and a hyperbola.) Descriptive geometry is a type of technical drawing and the branch of geometry which allows the representation of three-dimensional objects in two dimensions by using a specific set of procedures. The resulting techniques are important for engineering, architecture, design and in art. The theoretical basis for descriptive geometry is provided by planar geometric projections. The earliest known publication on the technique was "Underweysung der Messung mit dem Zirckel und Richtscheyt" (Observation of the measurement with the compass and spirit level), published in Linien, Nuremberg: 1525, by Albrecht Dürer. Italian architect Guarino Guarini was also a pioneer of projective and descriptive geometry, as is clear from his Placita Philosophica (1665), Euclides Adauctus (1671) and Architettura Civile (1686—not published until 1737). Gaspard Monge (