An interactive applet and associated web page that demonstrate how to construct the two possible tangents to a circle from an external given point, using compass and straightedge. It starts with the given circle and external point, and in an animation that can run without stopping or single stepped, shows how to construct the two tangent lines. The text on the page contains written step-by-step instructions that can be printed.

Has link to a printable worksheet with two related problems. Suitable for class handout or homework.

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.