# How to connect 9 dots with 4 straight lines?

The segments can also cut each other.

I have tried and tried but I can do it with 5 segments only.

• hint: two lines are out the square – chenbai Feb 26 '15 at 12:49
• Three horizontal segments and one vertical segment, each passing through three of the points, seem to do the job. I guess it depends on what you mean by "unite them all". What does it mean for a bunch of line segments to "unite" a set of points? – bof Feb 26 '15 at 12:51
• @bof I believe OP meant a polygonal chain of 4 segments containing all the given dots. – Andrei Rykhalski Feb 26 '15 at 12:52
• @AndreiRykhalski How did you figure that out? Did you deduce that from the statement of the question? Or are you just assuming that the OP must be referring to a familiar problem which involves the same diagram? – bof Feb 26 '15 at 12:54
• In my opinion we do the askers no favors by reading their minds and answering the question they meant to ask; rather we should try to urge them to formulate their questions correctly and clearly. – bof Feb 26 '15 at 13:00