Area Under the Arc

The Area Under Arc function is found only in the Construct menu at the top of the main window.  Here are the steps:

1. Select an arc drawn over a function.
2. Select Construct / Area Under Arc.

A filled area is created between the arc and the X axis.  The necessary lines and points containing the area are automatically added.

Drag the handles of the original function and the area under the curve changes accordingly.

 

This is a great way to illustrate the definite integral.

Note: this only works for arcs drawn on functions.  For arcs drawn on conics, create the sides with the Draw / Line Segment, select all sides and use the Construct / Polygon tool.   See also:  instructions for creating curvilinear polygons.