This video shows how to construct a regular hexagon inside a circle, using only a ruler and a compass. The circle become the circumcircle of the hexagon. This is one of the simplest ruler-and-compass constructions of all, ideal for a beginner to the topic.
For more videos and math help, see http://www.dr-mikes-math-games-for-kids.com/
Music "Comedic Juggernaut" by Kevin MacLeod, http://www.incompetech.com