Nine dots – two lines
This page is designed to be read as a link from Creativity Diamond – Outside the box and will probably not make much sense if you haven’t either read that or my book Opening the Creativity Diamond. Please check them out and come back when you have. You’re welcome to stay but may feel as though you’re missing something!
As you can see, this is the use of the thick line trick from Nine Dots – one line but instead of covering all the dots just cover some of them then come back on yourself with a second thick line.
I’ve kept the lines transparent for clarity.
This is a perfectly fine solution but it took me some years to get to it. I frequently use the Nine Dots problem on training courses; one time I ended a walk through of five, four, three, one (and zero) with a comment to the effect I hadn’t ever seen a solution for two lines. Within seconds one of the people I was training suggested the answer here.
The moral to this tale? You can never stop learning and the trainer doesn’t know everything!