An interactive applet and associated web page that demonstrate how to construct the incircle of triangle using compass and straightedge. It starts with a given triangle, and using animation that can be run continuously or single step, shows how to first construct the incenter, then using that point, construct the incircle of the given triangle. 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.