• goto https://www.sagemath.org
• click on Download 9.2 icon
• follow the instructions
• start Sage Notebook server
  • Windows: open program SageMath XX Notebook
  • Linux: open a bash shell and run the command

    sage --notebook=jupyter

Right-click the link on the home page or wiki, and store the file on your computer:

Open Jupyter on your computer and click upload:

navigate to the file on your hard drive and select for upload:

select file by left click:

open the Sage-notebook in a new tab of your browser:

clicking “run” will run the selected cell. Here, the vectors M and D will be defined that specify the position of the reflector:

You can copy parts of a cell into a new cell and run them, or modify them and see what happens when you run them…

Have a look at these examples on the Sage server and at the solutions of representative problems on the present Wiki.

Let us know if this description works for you, and - if now - where you encountered problems.