The present paper describes an exercise for architecture students that has two objectives: (1) to present the different types of symmetry and introduce the importance of symmetric design in graphic and architectural composition; and (2) to describe an example of how common CAD tools can be customized and turned into specific symmetric design tools. The final aim is to show how computer drafting can be more efficient than hand drafting in certain cases, especially when the computer.s real-time shape computation abilities can be used to the designer.s help.