This action transform the current color-filled polygon to anthoer color-filled triangle with the same points. It's free transform so that the two polygon doesn't need to be congruent or equivelent.
Step 1. Click a polygon, the polygon is then selected.
Step 2. Drag the vertex of the polygon to another point. When the dragging is finished, right click the mouse and select OK on the popup menu.
JGEX Help