The ggb-file attached provides an illustration to particular (1-parameter) case of the Poncelet theorem for pentagram. The point Aon the plot can be pulled along the circomference and drag the whole of the construction so that the pentagram remains in- and circumscribed as in the very beginning. This property conserves under changes of the parameter u. The last operation was to remove the rays out from the circumference that I could not complete. I just could not find eraser. My question is, will anybody show me how to do this so that I can continue to compose the complete 3-parameter family?