An interactive applet and associated web page that provide step-by-step instructions on how to find the circumcircle of a triangle using only a compass and straightedge. The method used involves constructing the perpendicular bisectors of two of the triangle's sides. The bisectors intersect at the circumcenter of the triangle and from this the circumcircle is drawn.

The animation can be run either continuously like a video, or single stepped to allow classroom discussion and thought between steps.

Applet can be enlarged to full screen size for use with a classroom projector. After use in the classroom, student can access it again from any web browser at home or in the library with no login required.

This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.