This applet illustrates the repeated interpolation used in the De Casteljau algorithm.

How to use it: Use the mouse to place the control points (3 or more) for the Bezier curve, then use the Draw Curve button to draw the curve. You can also draw the polygons using the Draw Polygons button. The curves are obtained through repeated interpolation (see Fig. 8 in this issue). You can play around with the scrollbar to move t between 0 and 1, and see how it affects the polygons.