To interchange between the 2D and 3D mode, click on the tabs, found on the upper right hand corner of the interactive.
There are three shapes to explore in each mode. Use the scale factor slider to change the size of the purple shape in relation to the red one.
In the 2D mode, the dimensions of the red shape can we changed by clicking a dragging a green vertex.
In both modes, graphs and measures can be observed on the right panel by clicking on the tabs.