An interactive applet and associated web page that demonstrate the area of a segment of a circle - a part of a circle cut off by a chord. The applet shows a circle and a segment of that circle, the ends of which can be dragged to resize the segment. As you drag the endpoints, the area is continuously recalculated. The calculation can be turned off for class discussions. The web page has the formula for the area.

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.