You're solving a crossword and you need help with the clue A coordinate system using two or three mutually perpendicular axes with 20 letters? This clue and much more will you find here.
I'm from Germany and made this site to improve my English. If you have any suggestions, you're welcome to contact me.
Actually there are only less entries, but in the next weeks I will fill this solver with many clues.
If you can't find a solution, you're welcome to add it for others who needs help.