**four straight lines**, without lifting up the pencil from the paper where they are drawn, and without any tricks at all, like folding the paper, etc...

o o o o o o o o oThe question is: given the nine dots above, is it possible to connect them with

**only 3 straight lines**? The restrictions are the same, that is, without lifting up the pencil from the paper where they are drawn, no tricks allowed, and if you retrace a line, you must count one more line.

**Prove your answer!**

Note: this is a revisit to the problem Nine Dots already posted in this site and you can use that drawing for reference.