Almost Unschoolers: Sewing Card String Art Heart Pattern - Valentine's Math Meets Art
how to draw geometric cardioid & heart art in spirograph pattern - YouTube
Steven Strogatz on Twitter: "String art shows why this cardioid is a caustic: bright spots where many light rays (strings) intersect. http://t.co/gfz6IqohHe" / Twitter
String Art and Cardioid Explorer - Apps on Google Play
String Art and Cardioid Explorer - Apps on Google Play
how to make a cardioid out of string art
String Art,How to make Cardioid geometry /nephroid curve string art - YouTube