The book, design for the undergraduate and postgraduate semester courses on Computer Aided Design (CAD) in Mechanical, Civil and Computer Science and Engineering provides introduction and basics of CAD systems, hardware and software requirements, mathematical background on 2D primitives, 2D & 3D geometric transformations, parallel and non-parallel projections, planar and space curves, and 3D graphics. Supported by sufficient number of systematically solved examples with line sketches, it will inculcate better understanding and interest in CAD among the common engineering students.