Students enjoy making cards that can be given to friends or family. The Cardioid Card is a favorite project for Valentine's Day. Any mother would appreciate such a lovely card from a son or daughter! This project, as with many others, can be done in a number of ways. The fastest is for the teacher to give a blank copy of the pattern to the students, and let them decorate with colored pens or pencils. The geometry of the construction could be discussed, and the project would be a quick and easy amusement to celebrate the day. If there is more time, this project can be developed into a geometric lesson, including asking the students to do the construction themselves, using compass and straightedge or geometry software.

To create a cardioid, go to the following web page, scroll down towards the bottom of the page, and you will find the instructions for the constructing a cardioid at the following web page: http://mathforum.org/~sanders/geometry/GP21MoreCurves.html

Some textbooks even include a section on other curves, and this is a very interesting topic. These curves include the Nephroid, Deltoid, Strophoid and others.