Demonstration 3. Area maximum for convex pentagons

In this demo, you can move around three of the vertices of the pentagon directly, and you can move the two green vertices by changing the value of the variable "t" in the controls window.

This demo shows how it is possible to achieve any area ratio from 1/4 to 3/4 for a convex pentagon. In the next demo you can see that the area ratio for a non-convex pentagon is actually unbounded from above!