On the GeoGebra page there are two objects: 1. A line of symmetry 2. Half of a symmetrical shape This challenge is much easier if you turn on the GRID before beginning. Given the line of symmetry and half of the shape as clues, try to create the missing half of the shape using only the NEW POINT tool Toolbar Imageand the SEGMENT BETWEEN TWO POINTS tool Toolbar Image. After you have completed your construction, check your solution using the REFLECT OBJECT ABOUT LINE Toolbar Image tool.  After selecting this tool, just click on the original shape and then click on the line of symmetry.  The REFLECT OBJECT ABOUT LINE tool will create the missing half of the overall shape.   Check to see if your construction is indeed the missing half of the symmetrical shape.